Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1514216 > unrolled thread

Re: net/netlink: null-ptr-deref in netlink_dump/lock_acquire

Started byAndrey Konovalov <andreyknvl@google.com>
First post2016-11-03 01:20 +0100
Last post2016-11-03 18:30 +0100
Articles 7 — 3 participants

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.


Contents

  Re: net/netlink: null-ptr-deref in netlink_dump/lock_acquire Andrey Konovalov <andreyknvl@google.com> - 2016-11-03 01:20 +0100
    Re: net/netlink: null-ptr-deref in netlink_dump/lock_acquire Andrey Konovalov <andreyknvl@google.com> - 2016-11-03 03:40 +0100
      Re: net/netlink: null-ptr-deref in netlink_dump/lock_acquire Eric Dumazet <eric.dumazet@gmail.com> - 2016-11-03 04:00 +0100
        Re: net/netlink: null-ptr-deref in netlink_dump/lock_acquire Andrey Konovalov <andreyknvl@google.com> - 2016-11-03 04:10 +0100
          [PATCH net] netlink: netlink_diag_dump() runs without locks Eric Dumazet <eric.dumazet@gmail.com> - 2016-11-03 04:30 +0100
            Re: [PATCH net] netlink: netlink_diag_dump() runs without locks David Miller <davem@davemloft.net> - 2016-11-03 21:30 +0100
          Re: net/netlink: null-ptr-deref in netlink_dump/lock_acquire Andrey Konovalov <andreyknvl@google.com> - 2016-11-03 18:30 +0100

#1514216 — Re: net/netlink: null-ptr-deref in netlink_dump/lock_acquire

FromAndrey Konovalov <andreyknvl@google.com>
Date2016-11-03 01:20 +0100
SubjectRe: net/netlink: null-ptr-deref in netlink_dump/lock_acquire
Message-ID<szdV7-4Wk-3@gated-at.bofh.it>
On Wed, Oct 19, 2016 at 4:13 PM, Andrey Konovalov <andreyknvl@google.com> wrote:
> Hi,
>
> I've got the following error report while running the syzkaller fuzzer:
>
> kasan: CONFIG_KASAN_INLINE enabled
> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault: 0000 [#1] SMP KASAN
> Modules linked in:
> CPU: 1 PID: 3933 Comm: syz-executor Not tainted 4.9.0-rc1+ #230
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> task: ffff88006b79d800 task.stack: ffff88006bbc0000
> RIP: 0010:[<ffffffff8120872d>]  [<ffffffff8120872d>]
> __lock_acquire+0x12d/0x3450 kernel/locking/lockdep.c:3221
> RSP: 0018:ffff88006bbc7420  EFLAGS: 00010006
> RAX: 0000000000000046 RBX: dffffc0000000000 RCX: 0000000000000000
> RDX: 000000000000000c RSI: 0000000000000000 RDI: 0000000000000003
> RBP: ffff88006bbc75c0 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000000000 R11: ffffffff85f42240 R12: ffff88006b79d800
> R13: ffffffff84bfe4e0 R14: 0000000000000001 R15: 0000000000000060
> FS:  00007fd9c41cc700(0000) GS:ffff88006cd00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000451f80 CR3: 00000000638f0000 CR4: 00000000000006e0
> Stack:
>  0000000000000000 ffff88006bbc0000 ffff88006bbc8000 0000000000000000
>  0000000000000002 ffff88006b79d800 0000000000000000 ffff88006bbc7f48
>  ffffffff852adc60 0000000000000000 ffffffff852adc64 1ffffffff0b40135
> Call Trace:
>  [<ffffffff8120c5ae>] lock_acquire+0x17e/0x340 kernel/locking/lockdep.c:3746
>  [<     inline     >] __mutex_lock_common kernel/locking/mutex.c:521
>  [<ffffffff83fb6fe1>] mutex_lock_nested+0xb1/0x890 kernel/locking/mutex.c:621
>  [<ffffffff82db6fd0>] netlink_dump+0x50/0xac0 net/netlink/af_netlink.c:2067
>  [<ffffffff82dba381>] __netlink_dump_start+0x501/0x770
> net/netlink/af_netlink.c:2200
>  [<ffffffff82dc35b2>] genl_family_rcv_msg+0xa02/0xc80
> net/netlink/genetlink.c:595
>  [<ffffffff82dc39e6>] genl_rcv_msg+0x1b6/0x270 net/netlink/genetlink.c:658
>  [<ffffffff82dc1a70>] netlink_rcv_skb+0x2c0/0x3b0 net/netlink/af_netlink.c:2281
>  [<ffffffff82dc2b98>] genl_rcv+0x28/0x40 net/netlink/genetlink.c:669
>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1214
>  [<ffffffff82dc0329>] netlink_unicast+0x5a9/0x880 net/netlink/af_netlink.c:1240
>  [<ffffffff82dc0fb7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
>  [<ffffffff82b7075c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
>  [<ffffffff82b709c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
>  [<     inline     >] new_sync_write fs/read_write.c:499
>  [<ffffffff8151c944>] __vfs_write+0x334/0x570 fs/read_write.c:512
>  [<ffffffff8152045b>] vfs_write+0x17b/0x500 fs/read_write.c:560
>  [<     inline     >] SYSC_write fs/read_write.c:607
>  [<ffffffff81523d84>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
>  [<ffffffff83fc0141>] entry_SYSCALL_64_fastpath+0x1f/0xc2
> arch/x86/entry/entry_64.S:209
> Code: 0f 1f 44 00 00 f6 c4 02 0f 85 24 0a 00 00 44 8b 35 c9 61 8b 03
> 45 85 f6 74 2c 4c 89 fa 48 bb 00 00 00 00 00 fc ff df 48 c1 ea 03 <80>
> 3c 1a 00 0f 85 04 2f 00 00 49 81 3f a0 dc 2a 85 41 be 00 00
> RIP  [<ffffffff8120872d>] __lock_acquire+0x12d/0x3450
> kernel/locking/lockdep.c:3221
>  RSP <ffff88006bbc7420>
> ---[ end trace 685b3c182bf7f25c ]---
>
> The reproducer is attached.
>
> On commit 1a1891d762d6e64daf07b5be4817e3fbb29e3c59 (Oct 18).

(Adding more maintainers)

Still seeing this on 0c183d92b20b5c84ca655b45ef57b3318b83eb9e (Oct 31).

[toc] | [next] | [standalone]


#1514255

FromAndrey Konovalov <andreyknvl@google.com>
Date2016-11-03 03:40 +0100
Message-ID<szg6B-6bw-1@gated-at.bofh.it>
In reply to#1514216
On Thu, Nov 3, 2016 at 1:15 AM, Andrey Konovalov <andreyknvl@google.com> wrote:
> On Wed, Oct 19, 2016 at 4:13 PM, Andrey Konovalov <andreyknvl@google.com> wrote:
>> Hi,
>>
>> I've got the following error report while running the syzkaller fuzzer:
>>
>> kasan: CONFIG_KASAN_INLINE enabled
>> kasan: GPF could be caused by NULL-ptr deref or user memory access
>> general protection fault: 0000 [#1] SMP KASAN
>> Modules linked in:
>> CPU: 1 PID: 3933 Comm: syz-executor Not tainted 4.9.0-rc1+ #230
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>> task: ffff88006b79d800 task.stack: ffff88006bbc0000
>> RIP: 0010:[<ffffffff8120872d>]  [<ffffffff8120872d>]
>> __lock_acquire+0x12d/0x3450 kernel/locking/lockdep.c:3221
>> RSP: 0018:ffff88006bbc7420  EFLAGS: 00010006
>> RAX: 0000000000000046 RBX: dffffc0000000000 RCX: 0000000000000000
>> RDX: 000000000000000c RSI: 0000000000000000 RDI: 0000000000000003
>> RBP: ffff88006bbc75c0 R08: 0000000000000001 R09: 0000000000000000
>> R10: 0000000000000000 R11: ffffffff85f42240 R12: ffff88006b79d800
>> R13: ffffffff84bfe4e0 R14: 0000000000000001 R15: 0000000000000060
>> FS:  00007fd9c41cc700(0000) GS:ffff88006cd00000(0000) knlGS:0000000000000000
>> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 0000000000451f80 CR3: 00000000638f0000 CR4: 00000000000006e0
>> Stack:
>>  0000000000000000 ffff88006bbc0000 ffff88006bbc8000 0000000000000000
>>  0000000000000002 ffff88006b79d800 0000000000000000 ffff88006bbc7f48
>>  ffffffff852adc60 0000000000000000 ffffffff852adc64 1ffffffff0b40135
>> Call Trace:
>>  [<ffffffff8120c5ae>] lock_acquire+0x17e/0x340 kernel/locking/lockdep.c:3746
>>  [<     inline     >] __mutex_lock_common kernel/locking/mutex.c:521
>>  [<ffffffff83fb6fe1>] mutex_lock_nested+0xb1/0x890 kernel/locking/mutex.c:621
>>  [<ffffffff82db6fd0>] netlink_dump+0x50/0xac0 net/netlink/af_netlink.c:2067
>>  [<ffffffff82dba381>] __netlink_dump_start+0x501/0x770
>> net/netlink/af_netlink.c:2200
>>  [<ffffffff82dc35b2>] genl_family_rcv_msg+0xa02/0xc80
>> net/netlink/genetlink.c:595
>>  [<ffffffff82dc39e6>] genl_rcv_msg+0x1b6/0x270 net/netlink/genetlink.c:658
>>  [<ffffffff82dc1a70>] netlink_rcv_skb+0x2c0/0x3b0 net/netlink/af_netlink.c:2281
>>  [<ffffffff82dc2b98>] genl_rcv+0x28/0x40 net/netlink/genetlink.c:669
>>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1214
>>  [<ffffffff82dc0329>] netlink_unicast+0x5a9/0x880 net/netlink/af_netlink.c:1240
>>  [<ffffffff82dc0fb7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
>>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
>>  [<ffffffff82b7075c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
>>  [<ffffffff82b709c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
>>  [<     inline     >] new_sync_write fs/read_write.c:499
>>  [<ffffffff8151c944>] __vfs_write+0x334/0x570 fs/read_write.c:512
>>  [<ffffffff8152045b>] vfs_write+0x17b/0x500 fs/read_write.c:560
>>  [<     inline     >] SYSC_write fs/read_write.c:607
>>  [<ffffffff81523d84>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
>>  [<ffffffff83fc0141>] entry_SYSCALL_64_fastpath+0x1f/0xc2
>> arch/x86/entry/entry_64.S:209
>> Code: 0f 1f 44 00 00 f6 c4 02 0f 85 24 0a 00 00 44 8b 35 c9 61 8b 03
>> 45 85 f6 74 2c 4c 89 fa 48 bb 00 00 00 00 00 fc ff df 48 c1 ea 03 <80>
>> 3c 1a 00 0f 85 04 2f 00 00 49 81 3f a0 dc 2a 85 41 be 00 00
>> RIP  [<ffffffff8120872d>] __lock_acquire+0x12d/0x3450
>> kernel/locking/lockdep.c:3221
>>  RSP <ffff88006bbc7420>
>> ---[ end trace 685b3c182bf7f25c ]---
>>
>> The reproducer is attached.
>>
>> On commit 1a1891d762d6e64daf07b5be4817e3fbb29e3c59 (Oct 18).
>
> (Adding more maintainers)
>
> Still seeing this on 0c183d92b20b5c84ca655b45ef57b3318b83eb9e (Oct 31).

Here is another report that might be related:

=====================================
[ BUG: bad unlock balance detected! ]
4.9.0-rc3+ #336 Not tainted
-------------------------------------
syz-executor/4018 is trying to release lock ([   36.220068] nl_table_lock
) at:
[<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182
but there are no more locks to release!

other info that might help us debug this:
3 locks held by syz-executor/4018:
 #0: [   36.220068]  (
sock_diag_mutex[   36.220068] ){+.+.+.}
, at: [   36.220068] [<ffffffff82c3873b>] sock_diag_rcv+0x1b/0x40
 #1: [   36.220068]  (
sock_diag_table_mutex[   36.220068] ){+.+.+.}
, at: [   36.220068] [<ffffffff82c38e00>] sock_diag_rcv_msg+0x140/0x3a0
 #2: [   36.220068]  (
nlk->cb_mutex[   36.220068] ){+.+.+.}
, at: [   36.220068] [<ffffffff82db6600>] netlink_dump+0x50/0xac0

stack backtrace:
CPU: 1 PID: 4018 Comm: syz-executor Not tainted 4.9.0-rc3+ #336
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 ffff8800645df688 ffffffff81b46934 ffffffff84eb3e78 ffff88006ad85800
 ffffffff82dc8683 ffffffff84eb3e78 ffff8800645df6b8 ffffffff812043ca
 dffffc0000000000 ffff88006ad85ff8 ffff88006ad85fd0 00000000ffffffff
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
 [<ffffffff812043ca>] print_unlock_imbalance_bug+0x17a/0x1a0
kernel/locking/lockdep.c:3388
 [<     inline     >] __lock_release kernel/locking/lockdep.c:3512
 [<ffffffff8120cfd8>] lock_release+0x8e8/0xc60 kernel/locking/lockdep.c:3765
 [<     inline     >] __raw_read_unlock ./include/linux/rwlock_api_smp.h:225
 [<ffffffff83fc001a>] _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:255
 [<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182
 [<ffffffff82db6947>] netlink_dump+0x397/0xac0 net/netlink/af_netlink.c:2110
 [<ffffffff82db99b1>] __netlink_dump_start+0x501/0x770
net/netlink/af_netlink.c:2200
 [<     inline     >] netlink_dump_start ./include/linux/netlink.h:165
 [<ffffffff82dc75d1>] netlink_diag_handler_dump+0x191/0x220
net/netlink/diag.c:218
 [<     inline     >] __sock_diag_cmd net/core/sock_diag.c:239
 [<ffffffff82c38fd6>] sock_diag_rcv_msg+0x316/0x3a0 net/core/sock_diag.c:270
 [<ffffffff82dc10a0>] netlink_rcv_skb+0x2c0/0x3b0 net/netlink/af_netlink.c:2281
 [<ffffffff82c3874a>] sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:281
 [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1214
 [<ffffffff82dbf959>] netlink_unicast+0x5a9/0x880 net/netlink/af_netlink.c:1240
 [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
 [<     inline     >] sock_sendmsg_nosec net/socket.c:606
 [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
 [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
 [<     inline     >] new_sync_write fs/read_write.c:499
 [<ffffffff8151bd44>] __vfs_write+0x334/0x570 fs/read_write.c:512
 [<ffffffff8151f85b>] vfs_write+0x17b/0x500 fs/read_write.c:560
 [<     inline     >] SYSC_write fs/read_write.c:607
 [<ffffffff81523184>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
 [<ffffffff83fc0401>] entry_SYSCALL_64_fastpath+0x1f/0xc2
arch/x86/entry/entry_64.S:209
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4018 at net/core/skbuff.c:654[<        none
 >] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
Modules linked in:
CPU: 1 PID: 4018 Comm: syz-executor Not tainted 4.9.0-rc3+ #336
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 ffff8800645df920 ffffffff81b46934 0000000000000000 0000000000000000
 ffffffff84401fa0 0000000000000000 ffff8800645df968 ffffffff811112f7
 ffffffff83fb92f2 ffff88000000028e ffffffff84401fa0 000000000000028e
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
 [<ffffffff811112f7>] __warn+0x1a7/0x1f0 kernel/panic.c:550
 [<ffffffff8111150c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff82b885ea>] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
 [<ffffffff82b91815>] skb_release_all+0x15/0x60 net/core/skbuff.c:668
 [<     inline     >] __kfree_skb net/core/skbuff.c:684
 [<ffffffff82ba0175>] consume_skb+0x115/0x2e0 net/core/skbuff.c:757
 [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1215
 [<ffffffff82dbf961>] netlink_unicast+0x5b1/0x880 net/netlink/af_netlink.c:1240
 [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
 [<     inline     >] sock_sendmsg_nosec net/socket.c:606
 [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
 [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
 [<     inline     >] new_sync_write fs/read_write.c:499
 [<ffffffff8151bd44>] __vfs_write+0x334/0x570 fs/read_write.c:512
 [<ffffffff8151f85b>] vfs_write+0x17b/0x500 fs/read_write.c:560
 [<     inline     >] SYSC_write fs/read_write.c:607
 [<ffffffff81523184>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
 [<ffffffff83fc0401>] entry_SYSCALL_64_fastpath+0x1f/0xc2
arch/x86/entry/entry_64.S:209
---[ end trace bb9fa7cf182d59a5 ]---
BUG: scheduling while atomic: syz-executor/4018/0x7fffffff
INFO: lockdep is turned off.
Modules linked in:
CPU: 1 PID: 4018 Comm: syz-executor Tainted: G        W       4.9.0-rc3+ #336
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 ffff8800645dfe28 ffffffff81b46934 dffffc0000000000 000000007fffffff
 00000000000214c0 0000000000000001 ffff8800645dfe48 ffffffff8119113a
 ffff88006cd214c0 0000000000000000 ffff8800645dfec8 ffffffff83fb030a
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
 [<ffffffff8119113a>] __schedule_bug+0xfa/0x140 kernel/sched/core.c:3230
 [<     inline     >] schedule_debug kernel/sched/core.c:3245
 [<ffffffff83fb030a>] __schedule+0xfda/0x1ab0 kernel/sched/core.c:3345
 [<ffffffff83fb0e70>] schedule+0x90/0x1b0 kernel/sched/core.c:3457
 [<ffffffff810039e9>] exit_to_usermode_loop+0xc9/0x130
arch/x86/entry/common.c:149
 [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
 [<ffffffff81006298>] syscall_return_slowpath+0x1a8/0x1e0
arch/x86/entry/common.c:259
 [<ffffffff83fc04a2>] entry_SYSCALL_64_fastpath+0xc0/0xc2
arch/x86/entry/entry_64.S:244
NOHZ: local_softirq_pending 202
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4018 at net/core/skbuff.c:654[<        none
 >] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
Modules linked in:[   36.328353] CPU: 1 PID: 4018 Comm: syz-executor
Tainted: G        W       4.9.0-rc3+ #336
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 ffff8800645df920 ffffffff81b46934 0000000000000000 0000000000000000
 ffffffff84401fa0 0000000000000000 ffff8800645df968 ffffffff811112f7
 ffffffff83fb92f2 ffff88000000028e ffffffff84401fa0 000000000000028e
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
 [<ffffffff811112f7>] __warn+0x1a7/0x1f0 kernel/panic.c:550
 [<ffffffff8111150c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff82b885ea>] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
 [<ffffffff82b91815>] skb_release_all+0x15/0x60 net/core/skbuff.c:668
 [<     inline     >] __kfree_skb net/core/skbuff.c:684
 [<ffffffff82ba0175>] consume_skb+0x115/0x2e0 net/core/skbuff.c:757
 [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1215
 [<ffffffff82dbf961>] netlink_unicast+0x5b1/0x880 net/netlink/af_netlink.c:1240
 [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
 [<     inline     >] sock_sendmsg_nosec net/socket.c:606
 [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
 [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
 [<     inline     >] new_sync_write fs/read_write.c:499
 [<ffffffff8151bd44>] __vfs_write+0x334/0x570 fs/read_write.c:512
 [<ffffffff8151f85b>] vfs_write+0x17b/0x500 fs/read_write.c:560
 [<     inline     >] SYSC_write fs/read_write.c:607
 [<ffffffff81523184>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
 [<ffffffff83fc0401>] entry_SYSCALL_64_fastpath+0x1f/0xc2
arch/x86/entry/entry_64.S:209
---[ end trace bb9fa7cf182d59a6 ]---
BUG: sleeping function called from invalid context at
./include/linux/freezer.h:56
in_atomic(): 1, irqs_disabled(): 0, pid: 4018, name: syz-executor
INFO: lockdep is turned off.
CPU: 1 PID: 4018 Comm: syz-executor Tainted: G        W       4.9.0-rc3+ #336
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 ffff8800645dfbb0 ffffffff81b46934 ffff88006ad85800 ffff8800645d8000
 ffff88006ad85800 0000000000000000 ffff8800645dfbd8 ffffffff81192131
 ffff88006ad85800 ffffffff8404c140 0000000000000038 ffff8800645dfc18
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
 [<ffffffff81192131>] ___might_sleep+0x281/0x3c0 kernel/sched/core.c:7767
 [<ffffffff81192306>] __might_sleep+0x96/0x1a0 kernel/sched/core.c:7726
 [<     inline     >] try_to_freeze_unsafe ./include/linux/freezer.h:56
 [<     inline     >] try_to_freeze ./include/linux/freezer.h:66
 [<ffffffff81143849>] get_signal+0x129/0x15a0 kernel/signal.c:2147
 [<ffffffff81054aad>] do_signal+0x8d/0x1a30 arch/x86/kernel/signal.c:807
 [<ffffffff81003a05>] exit_to_usermode_loop+0xe5/0x130
arch/x86/entry/common.c:156
 [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
 [<ffffffff81006298>] syscall_return_slowpath+0x1a8/0x1e0
arch/x86/entry/common.c:259
 [<ffffffff83fc04a2>] entry_SYSCALL_64_fastpath+0xc0/0xc2
arch/x86/entry/entry_64.S:244
Kernel panic - not syncing: Aiee, killing interrupt handler!
CPU: 1 PID: 4018 Comm: syz-executor Tainted: G        W       4.9.0-rc3+ #336
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 ffff8800645df998 ffffffff81b46934 0000000000000003 dffffc0000000000
 dffffc0000000000 ffff8800645dfa04 ffff8800645dfa60 ffffffff8140bf7a
 0000000041b58ab3 ffffffff84797a7d ffffffff8140bdbe ffffffff00000000
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
 [<ffffffff8140bf7a>] panic+0x1bc/0x39d kernel/panic.c:179
 [<ffffffff8111cfd8>] do_exit+0x1b48/0x2ac0 kernel/exit.c:740
 [<ffffffff811222be>] do_group_exit+0x10e/0x340 kernel/exit.c:931
 [<ffffffff81143d54>] get_signal+0x634/0x15a0 kernel/signal.c:2307
 [<ffffffff81054aad>] do_signal+0x8d/0x1a30 arch/x86/kernel/signal.c:807
 [<ffffffff81003a05>] exit_to_usermode_loop+0xe5/0x130
arch/x86/entry/common.c:156
 [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
 [<ffffffff81006298>] syscall_return_slowpath+0x1a8/0x1e0
arch/x86/entry/common.c:259
 [<ffffffff83fc04a2>] entry_SYSCALL_64_fastpath+0xc0/0xc2
arch/x86/entry/entry_64.S:244
Kernel Offset: disabled
---[ end Kernel panic - not syncing: Aiee, killing interrupt handler!

[toc] | [prev] | [next] | [standalone]


#1514256

FromEric Dumazet <eric.dumazet@gmail.com>
Date2016-11-03 04:00 +0100
Message-ID<szgpY-6hH-3@gated-at.bofh.it>
In reply to#1514255
On Thu, 2016-11-03 at 03:36 +0100, Andrey Konovalov wrote:
> On Thu, Nov 3, 2016 at 1:15 AM, Andrey Konovalov <andreyknvl@google.com> wrote:
> > On Wed, Oct 19, 2016 at 4:13 PM, Andrey Konovalov <andreyknvl@google.com> wrote:
> >> Hi,
> >>
> >> I've got the following error report while running the syzkaller fuzzer:
> >>
> >> kasan: CONFIG_KASAN_INLINE enabled
> >> kasan: GPF could be caused by NULL-ptr deref or user memory access
> >> general protection fault: 0000 [#1] SMP KASAN
> >> Modules linked in:
> >> CPU: 1 PID: 3933 Comm: syz-executor Not tainted 4.9.0-rc1+ #230
> >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> >> task: ffff88006b79d800 task.stack: ffff88006bbc0000
> >> RIP: 0010:[<ffffffff8120872d>]  [<ffffffff8120872d>]
> >> __lock_acquire+0x12d/0x3450 kernel/locking/lockdep.c:3221
> >> RSP: 0018:ffff88006bbc7420  EFLAGS: 00010006
> >> RAX: 0000000000000046 RBX: dffffc0000000000 RCX: 0000000000000000
> >> RDX: 000000000000000c RSI: 0000000000000000 RDI: 0000000000000003
> >> RBP: ffff88006bbc75c0 R08: 0000000000000001 R09: 0000000000000000
> >> R10: 0000000000000000 R11: ffffffff85f42240 R12: ffff88006b79d800
> >> R13: ffffffff84bfe4e0 R14: 0000000000000001 R15: 0000000000000060
> >> FS:  00007fd9c41cc700(0000) GS:ffff88006cd00000(0000) knlGS:0000000000000000
> >> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> >> CR2: 0000000000451f80 CR3: 00000000638f0000 CR4: 00000000000006e0
> >> Stack:
> >>  0000000000000000 ffff88006bbc0000 ffff88006bbc8000 0000000000000000
> >>  0000000000000002 ffff88006b79d800 0000000000000000 ffff88006bbc7f48
> >>  ffffffff852adc60 0000000000000000 ffffffff852adc64 1ffffffff0b40135
> >> Call Trace:
> >>  [<ffffffff8120c5ae>] lock_acquire+0x17e/0x340 kernel/locking/lockdep.c:3746
> >>  [<     inline     >] __mutex_lock_common kernel/locking/mutex.c:521
> >>  [<ffffffff83fb6fe1>] mutex_lock_nested+0xb1/0x890 kernel/locking/mutex.c:621
> >>  [<ffffffff82db6fd0>] netlink_dump+0x50/0xac0 net/netlink/af_netlink.c:2067
> >>  [<ffffffff82dba381>] __netlink_dump_start+0x501/0x770
> >> net/netlink/af_netlink.c:2200
> >>  [<ffffffff82dc35b2>] genl_family_rcv_msg+0xa02/0xc80
> >> net/netlink/genetlink.c:595
> >>  [<ffffffff82dc39e6>] genl_rcv_msg+0x1b6/0x270 net/netlink/genetlink.c:658
> >>  [<ffffffff82dc1a70>] netlink_rcv_skb+0x2c0/0x3b0 net/netlink/af_netlink.c:2281
> >>  [<ffffffff82dc2b98>] genl_rcv+0x28/0x40 net/netlink/genetlink.c:669
> >>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1214
> >>  [<ffffffff82dc0329>] netlink_unicast+0x5a9/0x880 net/netlink/af_netlink.c:1240
> >>  [<ffffffff82dc0fb7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
> >>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
> >>  [<ffffffff82b7075c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
> >>  [<ffffffff82b709c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
> >>  [<     inline     >] new_sync_write fs/read_write.c:499
> >>  [<ffffffff8151c944>] __vfs_write+0x334/0x570 fs/read_write.c:512
> >>  [<ffffffff8152045b>] vfs_write+0x17b/0x500 fs/read_write.c:560
> >>  [<     inline     >] SYSC_write fs/read_write.c:607
> >>  [<ffffffff81523d84>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
> >>  [<ffffffff83fc0141>] entry_SYSCALL_64_fastpath+0x1f/0xc2
> >> arch/x86/entry/entry_64.S:209
> >> Code: 0f 1f 44 00 00 f6 c4 02 0f 85 24 0a 00 00 44 8b 35 c9 61 8b 03
> >> 45 85 f6 74 2c 4c 89 fa 48 bb 00 00 00 00 00 fc ff df 48 c1 ea 03 <80>
> >> 3c 1a 00 0f 85 04 2f 00 00 49 81 3f a0 dc 2a 85 41 be 00 00
> >> RIP  [<ffffffff8120872d>] __lock_acquire+0x12d/0x3450
> >> kernel/locking/lockdep.c:3221
> >>  RSP <ffff88006bbc7420>
> >> ---[ end trace 685b3c182bf7f25c ]---
> >>
> >> The reproducer is attached.
> >>
> >> On commit 1a1891d762d6e64daf07b5be4817e3fbb29e3c59 (Oct 18).
> >
> > (Adding more maintainers)
> >
> > Still seeing this on 0c183d92b20b5c84ca655b45ef57b3318b83eb9e (Oct 31).
> 
> Here is another report that might be related:
> 
> =====================================
> [ BUG: bad unlock balance detected! ]
> 4.9.0-rc3+ #336 Not tainted
> -------------------------------------
> syz-executor/4018 is trying to release lock ([   36.220068] nl_table_lock
> ) at:
> [<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182
> but there are no more locks to release!
> 
> other info that might help us debug this:
> 3 locks held by syz-executor/4018:
>  #0: [   36.220068]  (
> sock_diag_mutex[   36.220068] ){+.+.+.}
> , at: [   36.220068] [<ffffffff82c3873b>] sock_diag_rcv+0x1b/0x40
>  #1: [   36.220068]  (
> sock_diag_table_mutex[   36.220068] ){+.+.+.}
> , at: [   36.220068] [<ffffffff82c38e00>] sock_diag_rcv_msg+0x140/0x3a0
>  #2: [   36.220068]  (
> nlk->cb_mutex[   36.220068] ){+.+.+.}
> , at: [   36.220068] [<ffffffff82db6600>] netlink_dump+0x50/0xac0
> 
> stack backtrace:
> CPU: 1 PID: 4018 Comm: syz-executor Not tainted 4.9.0-rc3+ #336
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>  ffff8800645df688 ffffffff81b46934 ffffffff84eb3e78 ffff88006ad85800
>  ffffffff82dc8683 ffffffff84eb3e78 ffff8800645df6b8 ffffffff812043ca
>  dffffc0000000000 ffff88006ad85ff8 ffff88006ad85fd0 00000000ffffffff
> Call Trace:
>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>  [<ffffffff812043ca>] print_unlock_imbalance_bug+0x17a/0x1a0
> kernel/locking/lockdep.c:3388
>  [<     inline     >] __lock_release kernel/locking/lockdep.c:3512
>  [<ffffffff8120cfd8>] lock_release+0x8e8/0xc60 kernel/locking/lockdep.c:3765
>  [<     inline     >] __raw_read_unlock ./include/linux/rwlock_api_smp.h:225
>  [<ffffffff83fc001a>] _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:255
>  [<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182
>  [<ffffffff82db6947>] netlink_dump+0x397/0xac0 net/netlink/af_netlink.c:2110
>  [<ffffffff82db99b1>] __netlink_dump_start+0x501/0x770
> net/netlink/af_netlink.c:2200
>  [<     inline     >] netlink_dump_start ./include/linux/netlink.h:165
>  [<ffffffff82dc75d1>] netlink_diag_handler_dump+0x191/0x220
> net/netlink/diag.c:218
>  [<     inline     >] __sock_diag_cmd net/core/sock_diag.c:239
>  [<ffffffff82c38fd6>] sock_diag_rcv_msg+0x316/0x3a0 net/core/sock_diag.c:270
>  [<ffffffff82dc10a0>] netlink_rcv_skb+0x2c0/0x3b0 net/netlink/af_netlink.c:2281
>  [<ffffffff82c3874a>] sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:281
>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1214
>  [<ffffffff82dbf959>] netlink_unicast+0x5a9/0x880 net/netlink/af_netlink.c:1240
>  [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
>  [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
>  [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
>  [<     inline     >] new_sync_write fs/read_write.c:499
>  [<ffffffff8151bd44>] __vfs_write+0x334/0x570 fs/read_write.c:512
>  [<ffffffff8151f85b>] vfs_write+0x17b/0x500 fs/read_write.c:560
>  [<     inline     >] SYSC_write fs/read_write.c:607
>  [<ffffffff81523184>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
>  [<ffffffff83fc0401>] entry_SYSCALL_64_fastpath+0x1f/0xc2
> arch/x86/entry/entry_64.S:209
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 4018 at net/core/skbuff.c:654[<        none
>  >] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
> Modules linked in:
> CPU: 1 PID: 4018 Comm: syz-executor Not tainted 4.9.0-rc3+ #336
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>  ffff8800645df920 ffffffff81b46934 0000000000000000 0000000000000000
>  ffffffff84401fa0 0000000000000000 ffff8800645df968 ffffffff811112f7
>  ffffffff83fb92f2 ffff88000000028e ffffffff84401fa0 000000000000028e
> Call Trace:
>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>  [<ffffffff811112f7>] __warn+0x1a7/0x1f0 kernel/panic.c:550
>  [<ffffffff8111150c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
>  [<ffffffff82b885ea>] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
>  [<ffffffff82b91815>] skb_release_all+0x15/0x60 net/core/skbuff.c:668
>  [<     inline     >] __kfree_skb net/core/skbuff.c:684
>  [<ffffffff82ba0175>] consume_skb+0x115/0x2e0 net/core/skbuff.c:757
>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1215
>  [<ffffffff82dbf961>] netlink_unicast+0x5b1/0x880 net/netlink/af_netlink.c:1240
>  [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
>  [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
>  [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
>  [<     inline     >] new_sync_write fs/read_write.c:499
>  [<ffffffff8151bd44>] __vfs_write+0x334/0x570 fs/read_write.c:512
>  [<ffffffff8151f85b>] vfs_write+0x17b/0x500 fs/read_write.c:560
>  [<     inline     >] SYSC_write fs/read_write.c:607
>  [<ffffffff81523184>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
>  [<ffffffff83fc0401>] entry_SYSCALL_64_fastpath+0x1f/0xc2
> arch/x86/entry/entry_64.S:209
> ---[ end trace bb9fa7cf182d59a5 ]---
> BUG: scheduling while atomic: syz-executor/4018/0x7fffffff
> INFO: lockdep is turned off.
> Modules linked in:
> CPU: 1 PID: 4018 Comm: syz-executor Tainted: G        W       4.9.0-rc3+ #336
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>  ffff8800645dfe28 ffffffff81b46934 dffffc0000000000 000000007fffffff
>  00000000000214c0 0000000000000001 ffff8800645dfe48 ffffffff8119113a
>  ffff88006cd214c0 0000000000000000 ffff8800645dfec8 ffffffff83fb030a
> Call Trace:
>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>  [<ffffffff8119113a>] __schedule_bug+0xfa/0x140 kernel/sched/core.c:3230
>  [<     inline     >] schedule_debug kernel/sched/core.c:3245
>  [<ffffffff83fb030a>] __schedule+0xfda/0x1ab0 kernel/sched/core.c:3345
>  [<ffffffff83fb0e70>] schedule+0x90/0x1b0 kernel/sched/core.c:3457
>  [<ffffffff810039e9>] exit_to_usermode_loop+0xc9/0x130
> arch/x86/entry/common.c:149
>  [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
>  [<ffffffff81006298>] syscall_return_slowpath+0x1a8/0x1e0
> arch/x86/entry/common.c:259
>  [<ffffffff83fc04a2>] entry_SYSCALL_64_fastpath+0xc0/0xc2
> arch/x86/entry/entry_64.S:244
> NOHZ: local_softirq_pending 202
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 4018 at net/core/skbuff.c:654[<        none
>  >] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
> Modules linked in:[   36.328353] CPU: 1 PID: 4018 Comm: syz-executor
> Tainted: G        W       4.9.0-rc3+ #336
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>  ffff8800645df920 ffffffff81b46934 0000000000000000 0000000000000000
>  ffffffff84401fa0 0000000000000000 ffff8800645df968 ffffffff811112f7
>  ffffffff83fb92f2 ffff88000000028e ffffffff84401fa0 000000000000028e
> Call Trace:
>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>  [<ffffffff811112f7>] __warn+0x1a7/0x1f0 kernel/panic.c:550
>  [<ffffffff8111150c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
>  [<ffffffff82b885ea>] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
>  [<ffffffff82b91815>] skb_release_all+0x15/0x60 net/core/skbuff.c:668
>  [<     inline     >] __kfree_skb net/core/skbuff.c:684
>  [<ffffffff82ba0175>] consume_skb+0x115/0x2e0 net/core/skbuff.c:757
>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1215
>  [<ffffffff82dbf961>] netlink_unicast+0x5b1/0x880 net/netlink/af_netlink.c:1240
>  [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
>  [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
>  [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
>  [<     inline     >] new_sync_write fs/read_write.c:499
>  [<ffffffff8151bd44>] __vfs_write+0x334/0x570 fs/read_write.c:512
>  [<ffffffff8151f85b>] vfs_write+0x17b/0x500 fs/read_write.c:560
>  [<     inline     >] SYSC_write fs/read_write.c:607
>  [<ffffffff81523184>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
>  [<ffffffff83fc0401>] entry_SYSCALL_64_fastpath+0x1f/0xc2
> arch/x86/entry/entry_64.S:209
> ---[ end trace bb9fa7cf182d59a6 ]---
> BUG: sleeping function called from invalid context at
> ./include/linux/freezer.h:56
> in_atomic(): 1, irqs_disabled(): 0, pid: 4018, name: syz-executor
> INFO: lockdep is turned off.
> CPU: 1 PID: 4018 Comm: syz-executor Tainted: G        W       4.9.0-rc3+ #336
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>  ffff8800645dfbb0 ffffffff81b46934 ffff88006ad85800 ffff8800645d8000
>  ffff88006ad85800 0000000000000000 ffff8800645dfbd8 ffffffff81192131
>  ffff88006ad85800 ffffffff8404c140 0000000000000038 ffff8800645dfc18
> Call Trace:
>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>  [<ffffffff81192131>] ___might_sleep+0x281/0x3c0 kernel/sched/core.c:7767
>  [<ffffffff81192306>] __might_sleep+0x96/0x1a0 kernel/sched/core.c:7726
>  [<     inline     >] try_to_freeze_unsafe ./include/linux/freezer.h:56
>  [<     inline     >] try_to_freeze ./include/linux/freezer.h:66
>  [<ffffffff81143849>] get_signal+0x129/0x15a0 kernel/signal.c:2147
>  [<ffffffff81054aad>] do_signal+0x8d/0x1a30 arch/x86/kernel/signal.c:807
>  [<ffffffff81003a05>] exit_to_usermode_loop+0xe5/0x130
> arch/x86/entry/common.c:156
>  [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
>  [<ffffffff81006298>] syscall_return_slowpath+0x1a8/0x1e0
> arch/x86/entry/common.c:259
>  [<ffffffff83fc04a2>] entry_SYSCALL_64_fastpath+0xc0/0xc2
> arch/x86/entry/entry_64.S:244
> Kernel panic - not syncing: Aiee, killing interrupt handler!
> CPU: 1 PID: 4018 Comm: syz-executor Tainted: G        W       4.9.0-rc3+ #336
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>  ffff8800645df998 ffffffff81b46934 0000000000000003 dffffc0000000000
>  dffffc0000000000 ffff8800645dfa04 ffff8800645dfa60 ffffffff8140bf7a
>  0000000041b58ab3 ffffffff84797a7d ffffffff8140bdbe ffffffff00000000
> Call Trace:
>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>  [<ffffffff8140bf7a>] panic+0x1bc/0x39d kernel/panic.c:179
>  [<ffffffff8111cfd8>] do_exit+0x1b48/0x2ac0 kernel/exit.c:740
>  [<ffffffff811222be>] do_group_exit+0x10e/0x340 kernel/exit.c:931
>  [<ffffffff81143d54>] get_signal+0x634/0x15a0 kernel/signal.c:2307
>  [<ffffffff81054aad>] do_signal+0x8d/0x1a30 arch/x86/kernel/signal.c:807
>  [<ffffffff81003a05>] exit_to_usermode_loop+0xe5/0x130
> arch/x86/entry/common.c:156
>  [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
>  [<ffffffff81006298>] syscall_return_slowpath+0x1a8/0x1e0
> arch/x86/entry/common.c:259
>  [<ffffffff83fc04a2>] entry_SYSCALL_64_fastpath+0xc0/0xc2
> arch/x86/entry/entry_64.S:244
> Kernel Offset: disabled
> ---[ end Kernel panic - not syncing: Aiee, killing interrupt handler!


This is probably a leftover after commit
ad202074320cd75b31b8cdb58cca0d4ef6aaea8a
("netlink: Use rhashtable walk interface in diag dump")

Please try this trivial fix :

diff --git a/net/netlink/diag.c b/net/netlink/diag.c
index b2f0e986a6f4..a5546249fb10 100644
--- a/net/netlink/diag.c
+++ b/net/netlink/diag.c
@@ -178,11 +178,8 @@ static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 		}
 		cb->args[1] = i;
 	} else {
-		if (req->sdiag_protocol >= MAX_LINKS) {
-			read_unlock(&nl_table_lock);
-			rcu_read_unlock();
+		if (req->sdiag_protocol >= MAX_LINKS)
 			return -ENOENT;
-		}
 
 		err = __netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);
 	}

[toc] | [prev] | [next] | [standalone]


#1514264

FromAndrey Konovalov <andreyknvl@google.com>
Date2016-11-03 04:10 +0100
Message-ID<szgzE-6A7-25@gated-at.bofh.it>
In reply to#1514256
Hi Eric,

This fixes the second report, the first one is still there.
Apparently these are two separate issues.

For the second one:
Tested-by: Andrey Konovalov <andreyknvl@google.com>

Thanks for the fix!

On Thu, Nov 3, 2016 at 3:58 AM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> On Thu, 2016-11-03 at 03:36 +0100, Andrey Konovalov wrote:
>> On Thu, Nov 3, 2016 at 1:15 AM, Andrey Konovalov <andreyknvl@google.com> wrote:
>> > On Wed, Oct 19, 2016 at 4:13 PM, Andrey Konovalov <andreyknvl@google.com> wrote:
>> >> Hi,
>> >>
>> >> I've got the following error report while running the syzkaller fuzzer:
>> >>
>> >> kasan: CONFIG_KASAN_INLINE enabled
>> >> kasan: GPF could be caused by NULL-ptr deref or user memory access
>> >> general protection fault: 0000 [#1] SMP KASAN
>> >> Modules linked in:
>> >> CPU: 1 PID: 3933 Comm: syz-executor Not tainted 4.9.0-rc1+ #230
>> >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>> >> task: ffff88006b79d800 task.stack: ffff88006bbc0000
>> >> RIP: 0010:[<ffffffff8120872d>]  [<ffffffff8120872d>]
>> >> __lock_acquire+0x12d/0x3450 kernel/locking/lockdep.c:3221
>> >> RSP: 0018:ffff88006bbc7420  EFLAGS: 00010006
>> >> RAX: 0000000000000046 RBX: dffffc0000000000 RCX: 0000000000000000
>> >> RDX: 000000000000000c RSI: 0000000000000000 RDI: 0000000000000003
>> >> RBP: ffff88006bbc75c0 R08: 0000000000000001 R09: 0000000000000000
>> >> R10: 0000000000000000 R11: ffffffff85f42240 R12: ffff88006b79d800
>> >> R13: ffffffff84bfe4e0 R14: 0000000000000001 R15: 0000000000000060
>> >> FS:  00007fd9c41cc700(0000) GS:ffff88006cd00000(0000) knlGS:0000000000000000
>> >> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> >> CR2: 0000000000451f80 CR3: 00000000638f0000 CR4: 00000000000006e0
>> >> Stack:
>> >>  0000000000000000 ffff88006bbc0000 ffff88006bbc8000 0000000000000000
>> >>  0000000000000002 ffff88006b79d800 0000000000000000 ffff88006bbc7f48
>> >>  ffffffff852adc60 0000000000000000 ffffffff852adc64 1ffffffff0b40135
>> >> Call Trace:
>> >>  [<ffffffff8120c5ae>] lock_acquire+0x17e/0x340 kernel/locking/lockdep.c:3746
>> >>  [<     inline     >] __mutex_lock_common kernel/locking/mutex.c:521
>> >>  [<ffffffff83fb6fe1>] mutex_lock_nested+0xb1/0x890 kernel/locking/mutex.c:621
>> >>  [<ffffffff82db6fd0>] netlink_dump+0x50/0xac0 net/netlink/af_netlink.c:2067
>> >>  [<ffffffff82dba381>] __netlink_dump_start+0x501/0x770
>> >> net/netlink/af_netlink.c:2200
>> >>  [<ffffffff82dc35b2>] genl_family_rcv_msg+0xa02/0xc80
>> >> net/netlink/genetlink.c:595
>> >>  [<ffffffff82dc39e6>] genl_rcv_msg+0x1b6/0x270 net/netlink/genetlink.c:658
>> >>  [<ffffffff82dc1a70>] netlink_rcv_skb+0x2c0/0x3b0 net/netlink/af_netlink.c:2281
>> >>  [<ffffffff82dc2b98>] genl_rcv+0x28/0x40 net/netlink/genetlink.c:669
>> >>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1214
>> >>  [<ffffffff82dc0329>] netlink_unicast+0x5a9/0x880 net/netlink/af_netlink.c:1240
>> >>  [<ffffffff82dc0fb7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
>> >>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
>> >>  [<ffffffff82b7075c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
>> >>  [<ffffffff82b709c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
>> >>  [<     inline     >] new_sync_write fs/read_write.c:499
>> >>  [<ffffffff8151c944>] __vfs_write+0x334/0x570 fs/read_write.c:512
>> >>  [<ffffffff8152045b>] vfs_write+0x17b/0x500 fs/read_write.c:560
>> >>  [<     inline     >] SYSC_write fs/read_write.c:607
>> >>  [<ffffffff81523d84>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
>> >>  [<ffffffff83fc0141>] entry_SYSCALL_64_fastpath+0x1f/0xc2
>> >> arch/x86/entry/entry_64.S:209
>> >> Code: 0f 1f 44 00 00 f6 c4 02 0f 85 24 0a 00 00 44 8b 35 c9 61 8b 03
>> >> 45 85 f6 74 2c 4c 89 fa 48 bb 00 00 00 00 00 fc ff df 48 c1 ea 03 <80>
>> >> 3c 1a 00 0f 85 04 2f 00 00 49 81 3f a0 dc 2a 85 41 be 00 00
>> >> RIP  [<ffffffff8120872d>] __lock_acquire+0x12d/0x3450
>> >> kernel/locking/lockdep.c:3221
>> >>  RSP <ffff88006bbc7420>
>> >> ---[ end trace 685b3c182bf7f25c ]---
>> >>
>> >> The reproducer is attached.
>> >>
>> >> On commit 1a1891d762d6e64daf07b5be4817e3fbb29e3c59 (Oct 18).
>> >
>> > (Adding more maintainers)
>> >
>> > Still seeing this on 0c183d92b20b5c84ca655b45ef57b3318b83eb9e (Oct 31).
>>
>> Here is another report that might be related:
>>
>> =====================================
>> [ BUG: bad unlock balance detected! ]
>> 4.9.0-rc3+ #336 Not tainted
>> -------------------------------------
>> syz-executor/4018 is trying to release lock ([   36.220068] nl_table_lock
>> ) at:
>> [<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182
>> but there are no more locks to release!
>>
>> other info that might help us debug this:
>> 3 locks held by syz-executor/4018:
>>  #0: [   36.220068]  (
>> sock_diag_mutex[   36.220068] ){+.+.+.}
>> , at: [   36.220068] [<ffffffff82c3873b>] sock_diag_rcv+0x1b/0x40
>>  #1: [   36.220068]  (
>> sock_diag_table_mutex[   36.220068] ){+.+.+.}
>> , at: [   36.220068] [<ffffffff82c38e00>] sock_diag_rcv_msg+0x140/0x3a0
>>  #2: [   36.220068]  (
>> nlk->cb_mutex[   36.220068] ){+.+.+.}
>> , at: [   36.220068] [<ffffffff82db6600>] netlink_dump+0x50/0xac0
>>
>> stack backtrace:
>> CPU: 1 PID: 4018 Comm: syz-executor Not tainted 4.9.0-rc3+ #336
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>  ffff8800645df688 ffffffff81b46934 ffffffff84eb3e78 ffff88006ad85800
>>  ffffffff82dc8683 ffffffff84eb3e78 ffff8800645df6b8 ffffffff812043ca
>>  dffffc0000000000 ffff88006ad85ff8 ffff88006ad85fd0 00000000ffffffff
>> Call Trace:
>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>>  [<ffffffff812043ca>] print_unlock_imbalance_bug+0x17a/0x1a0
>> kernel/locking/lockdep.c:3388
>>  [<     inline     >] __lock_release kernel/locking/lockdep.c:3512
>>  [<ffffffff8120cfd8>] lock_release+0x8e8/0xc60 kernel/locking/lockdep.c:3765
>>  [<     inline     >] __raw_read_unlock ./include/linux/rwlock_api_smp.h:225
>>  [<ffffffff83fc001a>] _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:255
>>  [<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182
>>  [<ffffffff82db6947>] netlink_dump+0x397/0xac0 net/netlink/af_netlink.c:2110
>>  [<ffffffff82db99b1>] __netlink_dump_start+0x501/0x770
>> net/netlink/af_netlink.c:2200
>>  [<     inline     >] netlink_dump_start ./include/linux/netlink.h:165
>>  [<ffffffff82dc75d1>] netlink_diag_handler_dump+0x191/0x220
>> net/netlink/diag.c:218
>>  [<     inline     >] __sock_diag_cmd net/core/sock_diag.c:239
>>  [<ffffffff82c38fd6>] sock_diag_rcv_msg+0x316/0x3a0 net/core/sock_diag.c:270
>>  [<ffffffff82dc10a0>] netlink_rcv_skb+0x2c0/0x3b0 net/netlink/af_netlink.c:2281
>>  [<ffffffff82c3874a>] sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:281
>>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1214
>>  [<ffffffff82dbf959>] netlink_unicast+0x5a9/0x880 net/netlink/af_netlink.c:1240
>>  [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
>>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
>>  [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
>>  [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
>>  [<     inline     >] new_sync_write fs/read_write.c:499
>>  [<ffffffff8151bd44>] __vfs_write+0x334/0x570 fs/read_write.c:512
>>  [<ffffffff8151f85b>] vfs_write+0x17b/0x500 fs/read_write.c:560
>>  [<     inline     >] SYSC_write fs/read_write.c:607
>>  [<ffffffff81523184>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
>>  [<ffffffff83fc0401>] entry_SYSCALL_64_fastpath+0x1f/0xc2
>> arch/x86/entry/entry_64.S:209
>> ------------[ cut here ]------------
>> WARNING: CPU: 1 PID: 4018 at net/core/skbuff.c:654[<        none
>>  >] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
>> Modules linked in:
>> CPU: 1 PID: 4018 Comm: syz-executor Not tainted 4.9.0-rc3+ #336
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>  ffff8800645df920 ffffffff81b46934 0000000000000000 0000000000000000
>>  ffffffff84401fa0 0000000000000000 ffff8800645df968 ffffffff811112f7
>>  ffffffff83fb92f2 ffff88000000028e ffffffff84401fa0 000000000000028e
>> Call Trace:
>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>>  [<ffffffff811112f7>] __warn+0x1a7/0x1f0 kernel/panic.c:550
>>  [<ffffffff8111150c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
>>  [<ffffffff82b885ea>] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
>>  [<ffffffff82b91815>] skb_release_all+0x15/0x60 net/core/skbuff.c:668
>>  [<     inline     >] __kfree_skb net/core/skbuff.c:684
>>  [<ffffffff82ba0175>] consume_skb+0x115/0x2e0 net/core/skbuff.c:757
>>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1215
>>  [<ffffffff82dbf961>] netlink_unicast+0x5b1/0x880 net/netlink/af_netlink.c:1240
>>  [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
>>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
>>  [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
>>  [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
>>  [<     inline     >] new_sync_write fs/read_write.c:499
>>  [<ffffffff8151bd44>] __vfs_write+0x334/0x570 fs/read_write.c:512
>>  [<ffffffff8151f85b>] vfs_write+0x17b/0x500 fs/read_write.c:560
>>  [<     inline     >] SYSC_write fs/read_write.c:607
>>  [<ffffffff81523184>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
>>  [<ffffffff83fc0401>] entry_SYSCALL_64_fastpath+0x1f/0xc2
>> arch/x86/entry/entry_64.S:209
>> ---[ end trace bb9fa7cf182d59a5 ]---
>> BUG: scheduling while atomic: syz-executor/4018/0x7fffffff
>> INFO: lockdep is turned off.
>> Modules linked in:
>> CPU: 1 PID: 4018 Comm: syz-executor Tainted: G        W       4.9.0-rc3+ #336
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>  ffff8800645dfe28 ffffffff81b46934 dffffc0000000000 000000007fffffff
>>  00000000000214c0 0000000000000001 ffff8800645dfe48 ffffffff8119113a
>>  ffff88006cd214c0 0000000000000000 ffff8800645dfec8 ffffffff83fb030a
>> Call Trace:
>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>>  [<ffffffff8119113a>] __schedule_bug+0xfa/0x140 kernel/sched/core.c:3230
>>  [<     inline     >] schedule_debug kernel/sched/core.c:3245
>>  [<ffffffff83fb030a>] __schedule+0xfda/0x1ab0 kernel/sched/core.c:3345
>>  [<ffffffff83fb0e70>] schedule+0x90/0x1b0 kernel/sched/core.c:3457
>>  [<ffffffff810039e9>] exit_to_usermode_loop+0xc9/0x130
>> arch/x86/entry/common.c:149
>>  [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
>>  [<ffffffff81006298>] syscall_return_slowpath+0x1a8/0x1e0
>> arch/x86/entry/common.c:259
>>  [<ffffffff83fc04a2>] entry_SYSCALL_64_fastpath+0xc0/0xc2
>> arch/x86/entry/entry_64.S:244
>> NOHZ: local_softirq_pending 202
>> ------------[ cut here ]------------
>> WARNING: CPU: 1 PID: 4018 at net/core/skbuff.c:654[<        none
>>  >] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
>> Modules linked in:[   36.328353] CPU: 1 PID: 4018 Comm: syz-executor
>> Tainted: G        W       4.9.0-rc3+ #336
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>  ffff8800645df920 ffffffff81b46934 0000000000000000 0000000000000000
>>  ffffffff84401fa0 0000000000000000 ffff8800645df968 ffffffff811112f7
>>  ffffffff83fb92f2 ffff88000000028e ffffffff84401fa0 000000000000028e
>> Call Trace:
>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>>  [<ffffffff811112f7>] __warn+0x1a7/0x1f0 kernel/panic.c:550
>>  [<ffffffff8111150c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
>>  [<ffffffff82b885ea>] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
>>  [<ffffffff82b91815>] skb_release_all+0x15/0x60 net/core/skbuff.c:668
>>  [<     inline     >] __kfree_skb net/core/skbuff.c:684
>>  [<ffffffff82ba0175>] consume_skb+0x115/0x2e0 net/core/skbuff.c:757
>>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1215
>>  [<ffffffff82dbf961>] netlink_unicast+0x5b1/0x880 net/netlink/af_netlink.c:1240
>>  [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
>>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
>>  [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
>>  [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
>>  [<     inline     >] new_sync_write fs/read_write.c:499
>>  [<ffffffff8151bd44>] __vfs_write+0x334/0x570 fs/read_write.c:512
>>  [<ffffffff8151f85b>] vfs_write+0x17b/0x500 fs/read_write.c:560
>>  [<     inline     >] SYSC_write fs/read_write.c:607
>>  [<ffffffff81523184>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
>>  [<ffffffff83fc0401>] entry_SYSCALL_64_fastpath+0x1f/0xc2
>> arch/x86/entry/entry_64.S:209
>> ---[ end trace bb9fa7cf182d59a6 ]---
>> BUG: sleeping function called from invalid context at
>> ./include/linux/freezer.h:56
>> in_atomic(): 1, irqs_disabled(): 0, pid: 4018, name: syz-executor
>> INFO: lockdep is turned off.
>> CPU: 1 PID: 4018 Comm: syz-executor Tainted: G        W       4.9.0-rc3+ #336
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>  ffff8800645dfbb0 ffffffff81b46934 ffff88006ad85800 ffff8800645d8000
>>  ffff88006ad85800 0000000000000000 ffff8800645dfbd8 ffffffff81192131
>>  ffff88006ad85800 ffffffff8404c140 0000000000000038 ffff8800645dfc18
>> Call Trace:
>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>>  [<ffffffff81192131>] ___might_sleep+0x281/0x3c0 kernel/sched/core.c:7767
>>  [<ffffffff81192306>] __might_sleep+0x96/0x1a0 kernel/sched/core.c:7726
>>  [<     inline     >] try_to_freeze_unsafe ./include/linux/freezer.h:56
>>  [<     inline     >] try_to_freeze ./include/linux/freezer.h:66
>>  [<ffffffff81143849>] get_signal+0x129/0x15a0 kernel/signal.c:2147
>>  [<ffffffff81054aad>] do_signal+0x8d/0x1a30 arch/x86/kernel/signal.c:807
>>  [<ffffffff81003a05>] exit_to_usermode_loop+0xe5/0x130
>> arch/x86/entry/common.c:156
>>  [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
>>  [<ffffffff81006298>] syscall_return_slowpath+0x1a8/0x1e0
>> arch/x86/entry/common.c:259
>>  [<ffffffff83fc04a2>] entry_SYSCALL_64_fastpath+0xc0/0xc2
>> arch/x86/entry/entry_64.S:244
>> Kernel panic - not syncing: Aiee, killing interrupt handler!
>> CPU: 1 PID: 4018 Comm: syz-executor Tainted: G        W       4.9.0-rc3+ #336
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>  ffff8800645df998 ffffffff81b46934 0000000000000003 dffffc0000000000
>>  dffffc0000000000 ffff8800645dfa04 ffff8800645dfa60 ffffffff8140bf7a
>>  0000000041b58ab3 ffffffff84797a7d ffffffff8140bdbe ffffffff00000000
>> Call Trace:
>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>>  [<ffffffff8140bf7a>] panic+0x1bc/0x39d kernel/panic.c:179
>>  [<ffffffff8111cfd8>] do_exit+0x1b48/0x2ac0 kernel/exit.c:740
>>  [<ffffffff811222be>] do_group_exit+0x10e/0x340 kernel/exit.c:931
>>  [<ffffffff81143d54>] get_signal+0x634/0x15a0 kernel/signal.c:2307
>>  [<ffffffff81054aad>] do_signal+0x8d/0x1a30 arch/x86/kernel/signal.c:807
>>  [<ffffffff81003a05>] exit_to_usermode_loop+0xe5/0x130
>> arch/x86/entry/common.c:156
>>  [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
>>  [<ffffffff81006298>] syscall_return_slowpath+0x1a8/0x1e0
>> arch/x86/entry/common.c:259
>>  [<ffffffff83fc04a2>] entry_SYSCALL_64_fastpath+0xc0/0xc2
>> arch/x86/entry/entry_64.S:244
>> Kernel Offset: disabled
>> ---[ end Kernel panic - not syncing: Aiee, killing interrupt handler!
>
>
> This is probably a leftover after commit
> ad202074320cd75b31b8cdb58cca0d4ef6aaea8a
> ("netlink: Use rhashtable walk interface in diag dump")
>
> Please try this trivial fix :
>
> diff --git a/net/netlink/diag.c b/net/netlink/diag.c
> index b2f0e986a6f4..a5546249fb10 100644
> --- a/net/netlink/diag.c
> +++ b/net/netlink/diag.c
> @@ -178,11 +178,8 @@ static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
>                 }
>                 cb->args[1] = i;
>         } else {
> -               if (req->sdiag_protocol >= MAX_LINKS) {
> -                       read_unlock(&nl_table_lock);
> -                       rcu_read_unlock();
> +               if (req->sdiag_protocol >= MAX_LINKS)
>                         return -ENOENT;
> -               }
>
>                 err = __netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);
>         }
>
>

[toc] | [prev] | [next] | [standalone]


#1514269 — [PATCH net] netlink: netlink_diag_dump() runs without locks

FromEric Dumazet <eric.dumazet@gmail.com>
Date2016-11-03 04:30 +0100
Subject[PATCH net] netlink: netlink_diag_dump() runs without locks
Message-ID<szgSZ-6Mi-9@gated-at.bofh.it>
In reply to#1514264
From: Eric Dumazet <edumazet@google.com>

A recent commit removed locking from netlink_diag_dump() but forgot
one error case.

=====================================
[ BUG: bad unlock balance detected! ]
4.9.0-rc3+ #336 Not tainted
-------------------------------------
syz-executor/4018 is trying to release lock ([   36.220068] nl_table_lock
) at:
[<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182
but there are no more locks to release!

other info that might help us debug this:
3 locks held by syz-executor/4018:
 #0: [   36.220068]  (
sock_diag_mutex[   36.220068] ){+.+.+.}
, at: [   36.220068] [<ffffffff82c3873b>] sock_diag_rcv+0x1b/0x40
 #1: [   36.220068]  (
sock_diag_table_mutex[   36.220068] ){+.+.+.}
, at: [   36.220068] [<ffffffff82c38e00>] sock_diag_rcv_msg+0x140/0x3a0
 #2: [   36.220068]  (
nlk->cb_mutex[   36.220068] ){+.+.+.}
, at: [   36.220068] [<ffffffff82db6600>] netlink_dump+0x50/0xac0

stack backtrace:
CPU: 1 PID: 4018 Comm: syz-executor Not tainted 4.9.0-rc3+ #336
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 ffff8800645df688 ffffffff81b46934 ffffffff84eb3e78 ffff88006ad85800
 ffffffff82dc8683 ffffffff84eb3e78 ffff8800645df6b8 ffffffff812043ca
 dffffc0000000000 ffff88006ad85ff8 ffff88006ad85fd0 00000000ffffffff
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
 [<ffffffff812043ca>] print_unlock_imbalance_bug+0x17a/0x1a0
kernel/locking/lockdep.c:3388
 [<     inline     >] __lock_release kernel/locking/lockdep.c:3512
 [<ffffffff8120cfd8>] lock_release+0x8e8/0xc60 kernel/locking/lockdep.c:3765
 [<     inline     >] __raw_read_unlock ./include/linux/rwlock_api_smp.h:225
 [<ffffffff83fc001a>] _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:255
 [<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182
 [<ffffffff82db6947>] netlink_dump+0x397/0xac0 net/netlink/af_netlink.c:2110


Fixes: ad202074320c ("netlink: Use rhashtable walk interface in diag dump")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
---
 net/netlink/diag.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/net/netlink/diag.c b/net/netlink/diag.c
index b2f0e986a6f4..a5546249fb10 100644
--- a/net/netlink/diag.c
+++ b/net/netlink/diag.c
@@ -178,11 +178,8 @@ static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 		}
 		cb->args[1] = i;
 	} else {
-		if (req->sdiag_protocol >= MAX_LINKS) {
-			read_unlock(&nl_table_lock);
-			rcu_read_unlock();
+		if (req->sdiag_protocol >= MAX_LINKS)
 			return -ENOENT;
-		}
 
 		err = __netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);
 	}

[toc] | [prev] | [next] | [standalone]


#1514816 — Re: [PATCH net] netlink: netlink_diag_dump() runs without locks

FromDavid Miller <davem@davemloft.net>
Date2016-11-03 21:30 +0100
SubjectRe: [PATCH net] netlink: netlink_diag_dump() runs without locks
Message-ID<szwO5-i9-1@gated-at.bofh.it>
In reply to#1514269
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 02 Nov 2016 20:21:20 -0700

> From: Eric Dumazet <edumazet@google.com>
> 
> A recent commit removed locking from netlink_diag_dump() but forgot
> one error case.
 ...
> Fixes: ad202074320c ("netlink: Use rhashtable walk interface in diag dump")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Andrey Konovalov <andreyknvl@google.com>
> Tested-by: Andrey Konovalov <andreyknvl@google.com>

Applied.

[toc] | [prev] | [next] | [standalone]


#1514725

FromAndrey Konovalov <andreyknvl@google.com>
Date2016-11-03 18:30 +0100
Message-ID<sztZT-6TG-23@gated-at.bofh.it>
In reply to#1514264
Hi,

Another report that looks related:

[ INFO: possible circular locking dependency detected ]
4.9.0-rc3+ #344 Not tainted
-------------------------------------------------------
syz-executor/25526 is trying to acquire lock:
 ([  950.351060] &table[i].mutex
[<ffffffff82dcf798>] nfnl_lock+0x28/0x30 net/netfilter/nfnetlink.c:61

but task is already holding lock:
 ([  950.351060] rtnl_mutex
[<     inline     >] rtnl_lock net/core/rtnetlink.c:70
[<ffffffff82c15efb>] rtnetlink_rcv+0x1b/0x40 net/core/rtnetlink.c:4032

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

:
       [  950.351060] [<ffffffff8120c52e>] lock_acquire+0x17e/0x340
kernel/locking/lockdep.c:3746
       [  950.351060] [<     inline     >] __mutex_lock_common
kernel/locking/mutex.c:521
       [  950.351060] [<ffffffff83fb7221>]
mutex_lock_nested+0xb1/0x890 kernel/locking/mutex.c:621
       [  950.351060] [<ffffffff82c11297>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:70
       [  950.351060] [<ffffffff839fe31f>]
nl80211_get_reg_dump+0x5f/0x400 net/wireless/nl80211.c:6171
       [  950.351060] [<ffffffff82dc18d8>] genl_lock_dumpit+0x68/0x90
net/netlink/genetlink.c:517
       [  950.351060] [<ffffffff82db6947>] netlink_dump+0x397/0xac0
net/netlink/af_netlink.c:2110
       [  950.351060] [<ffffffff82db99b1>]
__netlink_dump_start+0x501/0x770 net/netlink/af_netlink.c:2200
       [  950.351060] [<ffffffff82dc2cb8>]
genl_family_rcv_msg+0xad8/0xc80 net/netlink/genetlink.c:584
       [  950.351060] [<ffffffff82dc3016>] genl_rcv_msg+0x1b6/0x270
net/netlink/genetlink.c:658
       [  950.351060] [<ffffffff82dc10a0>] netlink_rcv_skb+0x2c0/0x3b0
net/netlink/af_netlink.c:2281
       [  950.351060] [<ffffffff82dc21c8>] genl_rcv+0x28/0x40
net/netlink/genetlink.c:669
       [  950.351060] [<     inline     >] netlink_unicast_kernel
net/netlink/af_netlink.c:1214
       [  950.351060] [<ffffffff82dbf959>] netlink_unicast+0x5a9/0x880
net/netlink/af_netlink.c:1240
       [  950.351060] [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0
net/netlink/af_netlink.c:1786
       [  950.351060] [<     inline     >] sock_sendmsg_nosec net/socket.c:606
       [  950.351060] [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110
net/socket.c:616
       [  950.351060] [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0
net/socket.c:814
       [  950.351060] [<     inline     >] new_sync_write fs/read_write.c:499
       [  950.351060] [<ffffffff8151bd44>] __vfs_write+0x334/0x570
fs/read_write.c:512
       [  950.351060] [<ffffffff8151f85b>] vfs_write+0x17b/0x500
fs/read_write.c:560
       [  950.351060] [<     inline     >] SYSC_write fs/read_write.c:607
       [  950.351060] [<ffffffff81523184>] SyS_write+0xd4/0x1a0
fs/read_write.c:599
       [  950.351060] [<ffffffff83fc0281>] entry_SYSCALL_64_fastpath+0x1f/0xc2

:
       [  950.351060] [<ffffffff8120c52e>] lock_acquire+0x17e/0x340
kernel/locking/lockdep.c:3746
       [  950.351060] [<     inline     >] __mutex_lock_common
kernel/locking/mutex.c:521
       [  950.351060] [<ffffffff83fb7221>]
mutex_lock_nested+0xb1/0x890 kernel/locking/mutex.c:621
       [  950.351060] [<     inline     >] genl_lock net/netlink/genetlink.c:31
       [  950.351060] [<ffffffff82dc18b1>] genl_lock_dumpit+0x41/0x90
net/netlink/genetlink.c:516
       [  950.351060] [<ffffffff82db6947>] netlink_dump+0x397/0xac0
net/netlink/af_netlink.c:2110
       [  950.351060] [<ffffffff82db99b1>]
__netlink_dump_start+0x501/0x770 net/netlink/af_netlink.c:2200
       [  950.351060] [<ffffffff82dc2cb8>]
genl_family_rcv_msg+0xad8/0xc80 net/netlink/genetlink.c:584
       [  950.351060] [<ffffffff82dc3016>] genl_rcv_msg+0x1b6/0x270
net/netlink/genetlink.c:658
       [  950.351060] [<ffffffff82dc10a0>] netlink_rcv_skb+0x2c0/0x3b0
net/netlink/af_netlink.c:2281
       [  950.351060] [<ffffffff82dc21c8>] genl_rcv+0x28/0x40
net/netlink/genetlink.c:669
       [  950.351060] [<     inline     >] netlink_unicast_kernel
net/netlink/af_netlink.c:1214
       [  950.351060] [<ffffffff82dbf959>] netlink_unicast+0x5a9/0x880
net/netlink/af_netlink.c:1240
       [  950.351060] [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0
net/netlink/af_netlink.c:1786
       [  950.351060] [<     inline     >] sock_sendmsg_nosec net/socket.c:606
       [  950.351060] [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110
net/socket.c:616
       [  950.351060] [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0
net/socket.c:814
       [  950.351060] [<     inline     >] new_sync_write fs/read_write.c:499
       [  950.351060] [<ffffffff8151bd44>] __vfs_write+0x334/0x570
fs/read_write.c:512
       [  950.351060] [<ffffffff8151f85b>] vfs_write+0x17b/0x500
fs/read_write.c:560
       [  950.351060] [<     inline     >] SYSC_write fs/read_write.c:607
       [  950.351060] [<ffffffff81523184>] SyS_write+0xd4/0x1a0
fs/read_write.c:599
       [  950.351060] [<ffffffff83fc0281>] entry_SYSCALL_64_fastpath+0x1f/0xc2

:
       [  950.351060] [<ffffffff8120c52e>] lock_acquire+0x17e/0x340
kernel/locking/lockdep.c:3746
       [  950.351060] [<     inline     >] __mutex_lock_common
kernel/locking/mutex.c:521
       [  950.351060] [<ffffffff83fb7221>]
mutex_lock_nested+0xb1/0x890 kernel/locking/mutex.c:621
       [  950.351060] [<ffffffff82db95aa>]
__netlink_dump_start+0xfa/0x770 net/netlink/af_netlink.c:2170
       [  950.351060] [<     inline     >] netlink_dump_start
include/linux/netlink.h:165
       [  950.351060] [<ffffffff82e19309>]
ctnetlink_stat_ct_cpu+0xd9/0x130
net/netfilter/nf_conntrack_netlink.c:2045
       [  950.351060] [<ffffffff82dd1d80>]
nfnetlink_rcv_msg+0xa10/0xc10 net/netfilter/nfnetlink.c:212
       [  950.351060] [<ffffffff82dc10a0>] netlink_rcv_skb+0x2c0/0x3b0
net/netlink/af_netlink.c:2281
       [  950.351060] [<ffffffff82dd07e8>] nfnetlink_rcv+0x848/0x1170
net/netfilter/nfnetlink.c:474
       [  950.351060] [<     inline     >] netlink_unicast_kernel
net/netlink/af_netlink.c:1214
       [  950.351060] [<ffffffff82dbf959>] netlink_unicast+0x5a9/0x880
net/netlink/af_netlink.c:1240
       [  950.351060] [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0
net/netlink/af_netlink.c:1786
       [  950.351060] [<     inline     >] sock_sendmsg_nosec net/socket.c:606
       [  950.351060] [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110
net/socket.c:616
       [  950.351060] [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0
net/socket.c:814
       [  950.351060] [<     inline     >] new_sync_write fs/read_write.c:499
       [  950.351060] [<ffffffff8151bd44>] __vfs_write+0x334/0x570
fs/read_write.c:512
       [  950.351060] [<ffffffff8151f85b>] vfs_write+0x17b/0x500
fs/read_write.c:560
       [  950.351060] [<     inline     >] SYSC_write fs/read_write.c:607
       [  950.351060] [<ffffffff81523184>] SyS_write+0xd4/0x1a0
fs/read_write.c:599
       [  950.351060] [<ffffffff83fc0281>] entry_SYSCALL_64_fastpath+0x1f/0xc2

:
       [  950.351060] [<     inline     >] check_prev_add
kernel/locking/lockdep.c:1829
       [  950.351060] [<     inline     >] check_prevs_add
kernel/locking/lockdep.c:1939
       [  950.351060] [<     inline     >] validate_chain
kernel/locking/lockdep.c:2266
       [  950.351060] [<ffffffff8120b0ca>]
__lock_acquire+0x2b4a/0x3450 kernel/locking/lockdep.c:3335
       [  950.351060] [<ffffffff8120c52e>] lock_acquire+0x17e/0x340
kernel/locking/lockdep.c:3746
       [  950.351060] [<     inline     >] __mutex_lock_common
kernel/locking/mutex.c:521
       [  950.351060] [<ffffffff83fb7221>]
mutex_lock_nested+0xb1/0x890 kernel/locking/mutex.c:621
       [  950.351060] [<ffffffff82dcf798>] nfnl_lock+0x28/0x30
net/netfilter/nfnetlink.c:61
       [  950.351060] [<ffffffff82e847bf>]
nf_tables_netdev_event+0x14f/0x590
net/netfilter/nf_tables_netdev.c:122
       [  950.351060] [<ffffffff8117c131>]
notifier_call_chain+0x91/0x1a0 kernel/notifier.c:93
       [  950.351060] [<     inline     >] __raw_notifier_call_chain
kernel/notifier.c:394
       [  950.351060] [<ffffffff8117c2bd>]
raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
       [  950.351060] [<ffffffff82bc3851>]
call_netdevice_notifiers_info+0x51/0x90 net/core/dev.c:1645
       [  950.351060] [<     inline     >] call_netdevice_notifiers
net/core/dev.c:1661
       [  950.351060] [<ffffffff82be77c7>] dev_change_name+0x5d7/0x920
net/core/dev.c:1204
       [  950.351060] [<ffffffff82c171dd>] do_setlink+0x83d/0x30d0
net/core/rtnetlink.c:1993
       [  950.351060] [<ffffffff82c19ce0>] rtnl_setlink+0x270/0x330
net/core/rtnetlink.c:2231
       [  950.351060] [<ffffffff82c254a4>]
rtnetlink_rcv_msg+0x274/0x700 net/core/rtnetlink.c:4027
       [  950.351060] [<ffffffff82dc10a0>] netlink_rcv_skb+0x2c0/0x3b0
net/netlink/af_netlink.c:2281
       [  950.351060] [<ffffffff82c15f0a>] rtnetlink_rcv+0x2a/0x40
net/core/rtnetlink.c:4033
       [  950.351060] [<     inline     >] netlink_unicast_kernel
net/netlink/af_netlink.c:1214
       [  950.351060] [<ffffffff82dbf959>] netlink_unicast+0x5a9/0x880
net/netlink/af_netlink.c:1240
       [  950.351060] [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0
net/netlink/af_netlink.c:1786
       [  950.351060] [<     inline     >] sock_sendmsg_nosec net/socket.c:606
       [  950.351060] [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110
net/socket.c:616
       [  950.351060] [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0
net/socket.c:814
       [  950.351060] [<     inline     >] new_sync_write fs/read_write.c:499
       [  950.351060] [<ffffffff8151bd44>] __vfs_write+0x334/0x570
fs/read_write.c:512
       [  950.351060] [<ffffffff8151f85b>] vfs_write+0x17b/0x500
fs/read_write.c:560
       [  950.351060] [<     inline     >] SYSC_write fs/read_write.c:607
       [  950.351060] [<ffffffff81523184>] SyS_write+0xd4/0x1a0
fs/read_write.c:599
       [  950.351060] [<ffffffff81006465>] do_syscall_64+0x195/0x490
arch/x86/entry/common.c:280
       [  950.351060] [<ffffffff83fc0349>] return_from_SYSCALL_64+0x0/0x7a

other info that might help us debug this:

Chain exists of:


 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock([  950.351060] rtnl_mutex
);
                               lock([  950.351060] genl_mutex
);
                               lock([  950.351060] rtnl_mutex
);
  lock([  950.351060] &table[i].mutex
);

 *** DEADLOCK ***

1 lock held by syz-executor/25526:
 #0: [  950.351060]  (

stack backtrace:
CPU: 0 PID: 25526 Comm: syz-executor Not tainted 4.9.0-rc3+ #344
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 ffff8800692b6d30 ffffffff81b46934 ffffffff859bdf80 ffffffff859de740
 ffffffff859b3870 1ffffffff0bade82 ffff8800692b6d80 ffffffff81204cfd
 ffffffff859b3870 ffff88006859cca0 000000006859c480 ffff88006859cca0
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
 [<ffffffff81204cfd>] print_circular_bug+0x28d/0x350
kernel/locking/lockdep.c:1202
 [<     inline     >] check_prev_add kernel/locking/lockdep.c:1829
 [<     inline     >] check_prevs_add kernel/locking/lockdep.c:1939
 [<     inline     >] validate_chain kernel/locking/lockdep.c:2266
 [<ffffffff8120b0ca>] __lock_acquire+0x2b4a/0x3450 kernel/locking/lockdep.c:3335
 [<ffffffff8120c52e>] lock_acquire+0x17e/0x340 kernel/locking/lockdep.c:3746
 [<     inline     >] __mutex_lock_common kernel/locking/mutex.c:521
 [<ffffffff83fb7221>] mutex_lock_nested+0xb1/0x890 kernel/locking/mutex.c:621
 [<ffffffff82dcf798>] nfnl_lock+0x28/0x30 net/netfilter/nfnetlink.c:61
 [<ffffffff82e847bf>] nf_tables_netdev_event+0x14f/0x590
net/netfilter/nf_tables_netdev.c:122
 [<ffffffff8117c131>] notifier_call_chain+0x91/0x1a0 kernel/notifier.c:93
 [<     inline     >] __raw_notifier_call_chain kernel/notifier.c:394
 [<ffffffff8117c2bd>] raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
 [<ffffffff82bc3851>] call_netdevice_notifiers_info+0x51/0x90
net/core/dev.c:1645
 [<     inline     >] call_netdevice_notifiers net/core/dev.c:1661
 [<ffffffff82be77c7>] dev_change_name+0x5d7/0x920 net/core/dev.c:1204
 [<ffffffff82c171dd>] do_setlink+0x83d/0x30d0 net/core/rtnetlink.c:1993
 [<ffffffff82c19ce0>] rtnl_setlink+0x270/0x330 net/core/rtnetlink.c:2231
 [<ffffffff82c254a4>] rtnetlink_rcv_msg+0x274/0x700 net/core/rtnetlink.c:4027
 [<ffffffff82dc10a0>] netlink_rcv_skb+0x2c0/0x3b0 net/netlink/af_netlink.c:2281
 [<ffffffff82c15f0a>] rtnetlink_rcv+0x2a/0x40 net/core/rtnetlink.c:4033
 [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1214
 [<ffffffff82dbf959>] netlink_unicast+0x5a9/0x880 net/netlink/af_netlink.c:1240
 [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
 [<     inline     >] sock_sendmsg_nosec net/socket.c:606
 [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
 [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
 [<     inline     >] new_sync_write fs/read_write.c:499
 [<ffffffff8151bd44>] __vfs_write+0x334/0x570 fs/read_write.c:512
 [<ffffffff8151f85b>] vfs_write+0x17b/0x500 fs/read_write.c:560
 [<     inline     >] SYSC_write fs/read_write.c:607
 [<ffffffff81523184>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
 [<ffffffff81006465>] do_syscall_64+0x195/0x490 arch/x86/entry/common.c:280
 [<ffffffff83fc0349>] entry_SYSCALL64_slow_path+0x25/0x25

On Thu, Nov 3, 2016 at 4:08 AM, Andrey Konovalov <andreyknvl@google.com> wrote:
> Hi Eric,
>
> This fixes the second report, the first one is still there.
> Apparently these are two separate issues.
>
> For the second one:
> Tested-by: Andrey Konovalov <andreyknvl@google.com>
>
> Thanks for the fix!
>
> On Thu, Nov 3, 2016 at 3:58 AM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
>> On Thu, 2016-11-03 at 03:36 +0100, Andrey Konovalov wrote:
>>> On Thu, Nov 3, 2016 at 1:15 AM, Andrey Konovalov <andreyknvl@google.com> wrote:
>>> > On Wed, Oct 19, 2016 at 4:13 PM, Andrey Konovalov <andreyknvl@google.com> wrote:
>>> >> Hi,
>>> >>
>>> >> I've got the following error report while running the syzkaller fuzzer:
>>> >>
>>> >> kasan: CONFIG_KASAN_INLINE enabled
>>> >> kasan: GPF could be caused by NULL-ptr deref or user memory access
>>> >> general protection fault: 0000 [#1] SMP KASAN
>>> >> Modules linked in:
>>> >> CPU: 1 PID: 3933 Comm: syz-executor Not tainted 4.9.0-rc1+ #230
>>> >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>> >> task: ffff88006b79d800 task.stack: ffff88006bbc0000
>>> >> RIP: 0010:[<ffffffff8120872d>]  [<ffffffff8120872d>]
>>> >> __lock_acquire+0x12d/0x3450 kernel/locking/lockdep.c:3221
>>> >> RSP: 0018:ffff88006bbc7420  EFLAGS: 00010006
>>> >> RAX: 0000000000000046 RBX: dffffc0000000000 RCX: 0000000000000000
>>> >> RDX: 000000000000000c RSI: 0000000000000000 RDI: 0000000000000003
>>> >> RBP: ffff88006bbc75c0 R08: 0000000000000001 R09: 0000000000000000
>>> >> R10: 0000000000000000 R11: ffffffff85f42240 R12: ffff88006b79d800
>>> >> R13: ffffffff84bfe4e0 R14: 0000000000000001 R15: 0000000000000060
>>> >> FS:  00007fd9c41cc700(0000) GS:ffff88006cd00000(0000) knlGS:0000000000000000
>>> >> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> >> CR2: 0000000000451f80 CR3: 00000000638f0000 CR4: 00000000000006e0
>>> >> Stack:
>>> >>  0000000000000000 ffff88006bbc0000 ffff88006bbc8000 0000000000000000
>>> >>  0000000000000002 ffff88006b79d800 0000000000000000 ffff88006bbc7f48
>>> >>  ffffffff852adc60 0000000000000000 ffffffff852adc64 1ffffffff0b40135
>>> >> Call Trace:
>>> >>  [<ffffffff8120c5ae>] lock_acquire+0x17e/0x340 kernel/locking/lockdep.c:3746
>>> >>  [<     inline     >] __mutex_lock_common kernel/locking/mutex.c:521
>>> >>  [<ffffffff83fb6fe1>] mutex_lock_nested+0xb1/0x890 kernel/locking/mutex.c:621
>>> >>  [<ffffffff82db6fd0>] netlink_dump+0x50/0xac0 net/netlink/af_netlink.c:2067
>>> >>  [<ffffffff82dba381>] __netlink_dump_start+0x501/0x770
>>> >> net/netlink/af_netlink.c:2200
>>> >>  [<ffffffff82dc35b2>] genl_family_rcv_msg+0xa02/0xc80
>>> >> net/netlink/genetlink.c:595
>>> >>  [<ffffffff82dc39e6>] genl_rcv_msg+0x1b6/0x270 net/netlink/genetlink.c:658
>>> >>  [<ffffffff82dc1a70>] netlink_rcv_skb+0x2c0/0x3b0 net/netlink/af_netlink.c:2281
>>> >>  [<ffffffff82dc2b98>] genl_rcv+0x28/0x40 net/netlink/genetlink.c:669
>>> >>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1214
>>> >>  [<ffffffff82dc0329>] netlink_unicast+0x5a9/0x880 net/netlink/af_netlink.c:1240
>>> >>  [<ffffffff82dc0fb7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
>>> >>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
>>> >>  [<ffffffff82b7075c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
>>> >>  [<ffffffff82b709c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
>>> >>  [<     inline     >] new_sync_write fs/read_write.c:499
>>> >>  [<ffffffff8151c944>] __vfs_write+0x334/0x570 fs/read_write.c:512
>>> >>  [<ffffffff8152045b>] vfs_write+0x17b/0x500 fs/read_write.c:560
>>> >>  [<     inline     >] SYSC_write fs/read_write.c:607
>>> >>  [<ffffffff81523d84>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
>>> >>  [<ffffffff83fc0141>] entry_SYSCALL_64_fastpath+0x1f/0xc2
>>> >> arch/x86/entry/entry_64.S:209
>>> >> Code: 0f 1f 44 00 00 f6 c4 02 0f 85 24 0a 00 00 44 8b 35 c9 61 8b 03
>>> >> 45 85 f6 74 2c 4c 89 fa 48 bb 00 00 00 00 00 fc ff df 48 c1 ea 03 <80>
>>> >> 3c 1a 00 0f 85 04 2f 00 00 49 81 3f a0 dc 2a 85 41 be 00 00
>>> >> RIP  [<ffffffff8120872d>] __lock_acquire+0x12d/0x3450
>>> >> kernel/locking/lockdep.c:3221
>>> >>  RSP <ffff88006bbc7420>
>>> >> ---[ end trace 685b3c182bf7f25c ]---
>>> >>
>>> >> The reproducer is attached.
>>> >>
>>> >> On commit 1a1891d762d6e64daf07b5be4817e3fbb29e3c59 (Oct 18).
>>> >
>>> > (Adding more maintainers)
>>> >
>>> > Still seeing this on 0c183d92b20b5c84ca655b45ef57b3318b83eb9e (Oct 31).
>>>
>>> Here is another report that might be related:
>>>
>>> =====================================
>>> [ BUG: bad unlock balance detected! ]
>>> 4.9.0-rc3+ #336 Not tainted
>>> -------------------------------------
>>> syz-executor/4018 is trying to release lock ([   36.220068] nl_table_lock
>>> ) at:
>>> [<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182
>>> but there are no more locks to release!
>>>
>>> other info that might help us debug this:
>>> 3 locks held by syz-executor/4018:
>>>  #0: [   36.220068]  (
>>> sock_diag_mutex[   36.220068] ){+.+.+.}
>>> , at: [   36.220068] [<ffffffff82c3873b>] sock_diag_rcv+0x1b/0x40
>>>  #1: [   36.220068]  (
>>> sock_diag_table_mutex[   36.220068] ){+.+.+.}
>>> , at: [   36.220068] [<ffffffff82c38e00>] sock_diag_rcv_msg+0x140/0x3a0
>>>  #2: [   36.220068]  (
>>> nlk->cb_mutex[   36.220068] ){+.+.+.}
>>> , at: [   36.220068] [<ffffffff82db6600>] netlink_dump+0x50/0xac0
>>>
>>> stack backtrace:
>>> CPU: 1 PID: 4018 Comm: syz-executor Not tainted 4.9.0-rc3+ #336
>>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>>  ffff8800645df688 ffffffff81b46934 ffffffff84eb3e78 ffff88006ad85800
>>>  ffffffff82dc8683 ffffffff84eb3e78 ffff8800645df6b8 ffffffff812043ca
>>>  dffffc0000000000 ffff88006ad85ff8 ffff88006ad85fd0 00000000ffffffff
>>> Call Trace:
>>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>>>  [<ffffffff812043ca>] print_unlock_imbalance_bug+0x17a/0x1a0
>>> kernel/locking/lockdep.c:3388
>>>  [<     inline     >] __lock_release kernel/locking/lockdep.c:3512
>>>  [<ffffffff8120cfd8>] lock_release+0x8e8/0xc60 kernel/locking/lockdep.c:3765
>>>  [<     inline     >] __raw_read_unlock ./include/linux/rwlock_api_smp.h:225
>>>  [<ffffffff83fc001a>] _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:255
>>>  [<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182
>>>  [<ffffffff82db6947>] netlink_dump+0x397/0xac0 net/netlink/af_netlink.c:2110
>>>  [<ffffffff82db99b1>] __netlink_dump_start+0x501/0x770
>>> net/netlink/af_netlink.c:2200
>>>  [<     inline     >] netlink_dump_start ./include/linux/netlink.h:165
>>>  [<ffffffff82dc75d1>] netlink_diag_handler_dump+0x191/0x220
>>> net/netlink/diag.c:218
>>>  [<     inline     >] __sock_diag_cmd net/core/sock_diag.c:239
>>>  [<ffffffff82c38fd6>] sock_diag_rcv_msg+0x316/0x3a0 net/core/sock_diag.c:270
>>>  [<ffffffff82dc10a0>] netlink_rcv_skb+0x2c0/0x3b0 net/netlink/af_netlink.c:2281
>>>  [<ffffffff82c3874a>] sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:281
>>>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1214
>>>  [<ffffffff82dbf959>] netlink_unicast+0x5a9/0x880 net/netlink/af_netlink.c:1240
>>>  [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
>>>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
>>>  [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
>>>  [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
>>>  [<     inline     >] new_sync_write fs/read_write.c:499
>>>  [<ffffffff8151bd44>] __vfs_write+0x334/0x570 fs/read_write.c:512
>>>  [<ffffffff8151f85b>] vfs_write+0x17b/0x500 fs/read_write.c:560
>>>  [<     inline     >] SYSC_write fs/read_write.c:607
>>>  [<ffffffff81523184>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
>>>  [<ffffffff83fc0401>] entry_SYSCALL_64_fastpath+0x1f/0xc2
>>> arch/x86/entry/entry_64.S:209
>>> ------------[ cut here ]------------
>>> WARNING: CPU: 1 PID: 4018 at net/core/skbuff.c:654[<        none
>>>  >] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
>>> Modules linked in:
>>> CPU: 1 PID: 4018 Comm: syz-executor Not tainted 4.9.0-rc3+ #336
>>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>>  ffff8800645df920 ffffffff81b46934 0000000000000000 0000000000000000
>>>  ffffffff84401fa0 0000000000000000 ffff8800645df968 ffffffff811112f7
>>>  ffffffff83fb92f2 ffff88000000028e ffffffff84401fa0 000000000000028e
>>> Call Trace:
>>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>>>  [<ffffffff811112f7>] __warn+0x1a7/0x1f0 kernel/panic.c:550
>>>  [<ffffffff8111150c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
>>>  [<ffffffff82b885ea>] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
>>>  [<ffffffff82b91815>] skb_release_all+0x15/0x60 net/core/skbuff.c:668
>>>  [<     inline     >] __kfree_skb net/core/skbuff.c:684
>>>  [<ffffffff82ba0175>] consume_skb+0x115/0x2e0 net/core/skbuff.c:757
>>>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1215
>>>  [<ffffffff82dbf961>] netlink_unicast+0x5b1/0x880 net/netlink/af_netlink.c:1240
>>>  [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
>>>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
>>>  [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
>>>  [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
>>>  [<     inline     >] new_sync_write fs/read_write.c:499
>>>  [<ffffffff8151bd44>] __vfs_write+0x334/0x570 fs/read_write.c:512
>>>  [<ffffffff8151f85b>] vfs_write+0x17b/0x500 fs/read_write.c:560
>>>  [<     inline     >] SYSC_write fs/read_write.c:607
>>>  [<ffffffff81523184>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
>>>  [<ffffffff83fc0401>] entry_SYSCALL_64_fastpath+0x1f/0xc2
>>> arch/x86/entry/entry_64.S:209
>>> ---[ end trace bb9fa7cf182d59a5 ]---
>>> BUG: scheduling while atomic: syz-executor/4018/0x7fffffff
>>> INFO: lockdep is turned off.
>>> Modules linked in:
>>> CPU: 1 PID: 4018 Comm: syz-executor Tainted: G        W       4.9.0-rc3+ #336
>>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>>  ffff8800645dfe28 ffffffff81b46934 dffffc0000000000 000000007fffffff
>>>  00000000000214c0 0000000000000001 ffff8800645dfe48 ffffffff8119113a
>>>  ffff88006cd214c0 0000000000000000 ffff8800645dfec8 ffffffff83fb030a
>>> Call Trace:
>>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>>>  [<ffffffff8119113a>] __schedule_bug+0xfa/0x140 kernel/sched/core.c:3230
>>>  [<     inline     >] schedule_debug kernel/sched/core.c:3245
>>>  [<ffffffff83fb030a>] __schedule+0xfda/0x1ab0 kernel/sched/core.c:3345
>>>  [<ffffffff83fb0e70>] schedule+0x90/0x1b0 kernel/sched/core.c:3457
>>>  [<ffffffff810039e9>] exit_to_usermode_loop+0xc9/0x130
>>> arch/x86/entry/common.c:149
>>>  [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
>>>  [<ffffffff81006298>] syscall_return_slowpath+0x1a8/0x1e0
>>> arch/x86/entry/common.c:259
>>>  [<ffffffff83fc04a2>] entry_SYSCALL_64_fastpath+0xc0/0xc2
>>> arch/x86/entry/entry_64.S:244
>>> NOHZ: local_softirq_pending 202
>>> ------------[ cut here ]------------
>>> WARNING: CPU: 1 PID: 4018 at net/core/skbuff.c:654[<        none
>>>  >] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
>>> Modules linked in:[   36.328353] CPU: 1 PID: 4018 Comm: syz-executor
>>> Tainted: G        W       4.9.0-rc3+ #336
>>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>>  ffff8800645df920 ffffffff81b46934 0000000000000000 0000000000000000
>>>  ffffffff84401fa0 0000000000000000 ffff8800645df968 ffffffff811112f7
>>>  ffffffff83fb92f2 ffff88000000028e ffffffff84401fa0 000000000000028e
>>> Call Trace:
>>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>>>  [<ffffffff811112f7>] __warn+0x1a7/0x1f0 kernel/panic.c:550
>>>  [<ffffffff8111150c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
>>>  [<ffffffff82b885ea>] skb_release_head_state+0x1ca/0x240 net/core/skbuff.c:654
>>>  [<ffffffff82b91815>] skb_release_all+0x15/0x60 net/core/skbuff.c:668
>>>  [<     inline     >] __kfree_skb net/core/skbuff.c:684
>>>  [<ffffffff82ba0175>] consume_skb+0x115/0x2e0 net/core/skbuff.c:757
>>>  [<     inline     >] netlink_unicast_kernel net/netlink/af_netlink.c:1215
>>>  [<ffffffff82dbf961>] netlink_unicast+0x5b1/0x880 net/netlink/af_netlink.c:1240
>>>  [<ffffffff82dc05e7>] netlink_sendmsg+0x9b7/0xce0 net/netlink/af_netlink.c:1786
>>>  [<     inline     >] sock_sendmsg_nosec net/socket.c:606
>>>  [<ffffffff82b6f75c>] sock_sendmsg+0xcc/0x110 net/socket.c:616
>>>  [<ffffffff82b6f9c1>] sock_write_iter+0x221/0x3b0 net/socket.c:814
>>>  [<     inline     >] new_sync_write fs/read_write.c:499
>>>  [<ffffffff8151bd44>] __vfs_write+0x334/0x570 fs/read_write.c:512
>>>  [<ffffffff8151f85b>] vfs_write+0x17b/0x500 fs/read_write.c:560
>>>  [<     inline     >] SYSC_write fs/read_write.c:607
>>>  [<ffffffff81523184>] SyS_write+0xd4/0x1a0 fs/read_write.c:599
>>>  [<ffffffff83fc0401>] entry_SYSCALL_64_fastpath+0x1f/0xc2
>>> arch/x86/entry/entry_64.S:209
>>> ---[ end trace bb9fa7cf182d59a6 ]---
>>> BUG: sleeping function called from invalid context at
>>> ./include/linux/freezer.h:56
>>> in_atomic(): 1, irqs_disabled(): 0, pid: 4018, name: syz-executor
>>> INFO: lockdep is turned off.
>>> CPU: 1 PID: 4018 Comm: syz-executor Tainted: G        W       4.9.0-rc3+ #336
>>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>>  ffff8800645dfbb0 ffffffff81b46934 ffff88006ad85800 ffff8800645d8000
>>>  ffff88006ad85800 0000000000000000 ffff8800645dfbd8 ffffffff81192131
>>>  ffff88006ad85800 ffffffff8404c140 0000000000000038 ffff8800645dfc18
>>> Call Trace:
>>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>>>  [<ffffffff81192131>] ___might_sleep+0x281/0x3c0 kernel/sched/core.c:7767
>>>  [<ffffffff81192306>] __might_sleep+0x96/0x1a0 kernel/sched/core.c:7726
>>>  [<     inline     >] try_to_freeze_unsafe ./include/linux/freezer.h:56
>>>  [<     inline     >] try_to_freeze ./include/linux/freezer.h:66
>>>  [<ffffffff81143849>] get_signal+0x129/0x15a0 kernel/signal.c:2147
>>>  [<ffffffff81054aad>] do_signal+0x8d/0x1a30 arch/x86/kernel/signal.c:807
>>>  [<ffffffff81003a05>] exit_to_usermode_loop+0xe5/0x130
>>> arch/x86/entry/common.c:156
>>>  [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
>>>  [<ffffffff81006298>] syscall_return_slowpath+0x1a8/0x1e0
>>> arch/x86/entry/common.c:259
>>>  [<ffffffff83fc04a2>] entry_SYSCALL_64_fastpath+0xc0/0xc2
>>> arch/x86/entry/entry_64.S:244
>>> Kernel panic - not syncing: Aiee, killing interrupt handler!
>>> CPU: 1 PID: 4018 Comm: syz-executor Tainted: G        W       4.9.0-rc3+ #336
>>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>>  ffff8800645df998 ffffffff81b46934 0000000000000003 dffffc0000000000
>>>  dffffc0000000000 ffff8800645dfa04 ffff8800645dfa60 ffffffff8140bf7a
>>>  0000000041b58ab3 ffffffff84797a7d ffffffff8140bdbe ffffffff00000000
>>> Call Trace:
>>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>>  [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
>>>  [<ffffffff8140bf7a>] panic+0x1bc/0x39d kernel/panic.c:179
>>>  [<ffffffff8111cfd8>] do_exit+0x1b48/0x2ac0 kernel/exit.c:740
>>>  [<ffffffff811222be>] do_group_exit+0x10e/0x340 kernel/exit.c:931
>>>  [<ffffffff81143d54>] get_signal+0x634/0x15a0 kernel/signal.c:2307
>>>  [<ffffffff81054aad>] do_signal+0x8d/0x1a30 arch/x86/kernel/signal.c:807
>>>  [<ffffffff81003a05>] exit_to_usermode_loop+0xe5/0x130
>>> arch/x86/entry/common.c:156
>>>  [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
>>>  [<ffffffff81006298>] syscall_return_slowpath+0x1a8/0x1e0
>>> arch/x86/entry/common.c:259
>>>  [<ffffffff83fc04a2>] entry_SYSCALL_64_fastpath+0xc0/0xc2
>>> arch/x86/entry/entry_64.S:244
>>> Kernel Offset: disabled
>>> ---[ end Kernel panic - not syncing: Aiee, killing interrupt handler!
>>
>>
>> This is probably a leftover after commit
>> ad202074320cd75b31b8cdb58cca0d4ef6aaea8a
>> ("netlink: Use rhashtable walk interface in diag dump")
>>
>> Please try this trivial fix :
>>
>> diff --git a/net/netlink/diag.c b/net/netlink/diag.c
>> index b2f0e986a6f4..a5546249fb10 100644
>> --- a/net/netlink/diag.c
>> +++ b/net/netlink/diag.c
>> @@ -178,11 +178,8 @@ static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
>>                 }
>>                 cb->args[1] = i;
>>         } else {
>> -               if (req->sdiag_protocol >= MAX_LINKS) {
>> -                       read_unlock(&nl_table_lock);
>> -                       rcu_read_unlock();
>> +               if (req->sdiag_protocol >= MAX_LINKS)
>>                         return -ENOENT;
>> -               }
>>
>>                 err = __netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);
>>         }
>>
>>

[toc] | [prev] | [standalone]


Back to top | Article view | linux.kernel


csiph-web