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Groups > linux.kernel > #1680400
| From | Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 4.4 030/101] block: fix module reference leak on put_disk() call for cgroups throttle |
| Date | 2017-07-03 17:10 +0200 |
| Message-ID | <tZb98-3e8-27@gated-at.bofh.it> (permalink) |
| References | <tZ9K1-27f-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Roman Pen <roman.penyaev@profitbricks.com>
commit 39a169b62b415390398291080dafe63aec751e0a upstream.
get_disk(),get_gendisk() calls have non explicit side effect: they
increase the reference on the disk owner module.
The following is the correct sequence how to get a disk reference and
to put it:
disk = get_gendisk(...);
/* use disk */
owner = disk->fops->owner;
put_disk(disk);
module_put(owner);
fs/block_dev.c is aware of this required module_put() call, but f.e.
blkg_conf_finish(), which is located in block/blk-cgroup.c, does not put
a module reference. To see a leakage in action cgroups throttle config
can be used. In the following script I'm removing throttle for /dev/ram0
(actually this is NOP, because throttle was never set for this device):
# lsmod | grep brd
brd 5175 0
# i=100; while [ $i -gt 0 ]; do echo "1:0 0" > \
/sys/fs/cgroup/blkio/blkio.throttle.read_bps_device; i=$(($i - 1)); \
done
# lsmod | grep brd
brd 5175 100
Now brd module has 100 references.
The issue is fixed by calling module_put() just right away put_disk().
Signed-off-by: Roman Pen <roman.penyaev@profitbricks.com>
Cc: Gi-Oh Kim <gi-oh.kim@profitbricks.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
block/blk-cgroup.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -788,6 +788,7 @@ int blkg_conf_prep(struct blkcg *blkcg,
{
struct gendisk *disk;
struct blkcg_gq *blkg;
+ struct module *owner;
unsigned int major, minor;
int key_len, part, ret;
char *body;
@@ -804,7 +805,9 @@ int blkg_conf_prep(struct blkcg *blkcg,
if (!disk)
return -ENODEV;
if (part) {
+ owner = disk->fops->owner;
put_disk(disk);
+ module_put(owner);
return -ENODEV;
}
@@ -820,7 +823,9 @@ int blkg_conf_prep(struct blkcg *blkcg,
ret = PTR_ERR(blkg);
rcu_read_unlock();
spin_unlock_irq(disk->queue->queue_lock);
+ owner = disk->fops->owner;
put_disk(disk);
+ module_put(owner);
/*
* If queue was bypassing, we should retry. Do so after a
* short msleep(). It isn't strictly necessary but queue
@@ -851,9 +856,13 @@ EXPORT_SYMBOL_GPL(blkg_conf_prep);
void blkg_conf_finish(struct blkg_conf_ctx *ctx)
__releases(ctx->disk->queue->queue_lock) __releases(rcu)
{
+ struct module *owner;
+
spin_unlock_irq(ctx->disk->queue->queue_lock);
rcu_read_unlock();
+ owner = ctx->disk->fops->owner;
put_disk(ctx->disk);
+ module_put(owner);
}
EXPORT_SYMBOL_GPL(blkg_conf_finish);
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[PATCH 4.4 000/101] 4.4.76-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 15:40 +0200
[PATCH 4.4 094/101] iommu/vt-d: Dont over-free page table directories Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 15:50 +0200
[PATCH 4.4 061/101] amd-xgbe: Check xgbe_init() return code Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 15:50 +0200
[PATCH 4.4 082/101] ravb: Fix use-after-free on `ifconfig eth0 down` Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 15:50 +0200
[PATCH 4.4 090/101] ARM: 8685/1: ensure memblock-limit is pmd-aligned Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 15:50 +0200
[PATCH 4.4 086/101] xfrm: Oops on error in pfkey_msg2xfrm_state() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 15:50 +0200
[PATCH 4.4 096/101] iommu/amd: Fix incorrect error handling in amd_iommu_bind_pasid() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 15:50 +0200
[PATCH 4.4 079/101] perf probe: Fix to show correct locations for events on modules Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 15:50 +0200
[PATCH 4.4 089/101] ARM64/ACPI: Fix BAD_MADT_GICC_ENTRY() macro implementation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 15:50 +0200
[PATCH 4.4 057/101] net: sctp: fix array overrun read on sctp_timer_tbl Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 15:50 +0200
Re: [PATCH 4.4 057/101] net: sctp: fix array overrun read on sctp_timer_tbl Ben Hutchings <ben.hutchings@codethink.co.uk> - 2017-07-04 20:50 +0200
Re: [PATCH 4.4 057/101] net: sctp: fix array overrun read on sctp_timer_tbl Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-05 14:20 +0200
[PATCH 4.4 085/101] xfrm: NULL dereference on allocation failure Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 15:50 +0200
[PATCH 4.4 095/101] iommu: Handle default domain attach failure Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 15:50 +0200
Re: [PATCH 4.4 095/101] iommu: Handle default domain attach failure Ben Hutchings <ben.hutchings@codethink.co.uk> - 2017-07-05 21:00 +0200
[PATCH 4.4 053/101] gianfar: Do not reuse pages from emergency reserve Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 16:50 +0200
[PATCH 4.4 098/101] KVM: x86: fix emulation of RSM and IRET instructions Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 16:50 +0200
[PATCH 4.4 060/101] platform/x86: ideapad-laptop: handle ACPI event 1 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 16:50 +0200
[PATCH 4.4 091/101] x86/mpx: Correctly report do_mpx_bt_fault() failures to user-space Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 16:50 +0200
[PATCH 4.4 062/101] net: dsa: Check return value of phy_connect_direct() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 16:50 +0200
[PATCH 4.4 059/101] scsi: virtio_scsi: Reject commands when virtqueue is broken Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 16:50 +0200
[PATCH 4.4 058/101] xen-netfront: Fix Rx stall during network stress and OOM Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 16:50 +0200
[PATCH 4.4 097/101] cpufreq: s3c2416: double free on driver init error path Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 16:50 +0200
[PATCH 4.4 087/101] watchdog: bcm281xx: Fix use of uninitialized spinlock. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:00 +0200
[PATCH 4.4 055/101] virtio_console: fix a crash in config_work_handler Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:00 +0200
[PATCH 4.4 056/101] swiotlb-xen: update dev_addr after swapping pages Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:00 +0200
[PATCH 4.4 093/101] ocfs2: o2hb: revert hb threshold to keep compatible Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:00 +0200
[PATCH 4.4 076/101] swiotlb: ensure that page-sized mappings are page-aligned Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:00 +0200
[PATCH 4.4 080/101] net/mlx4_core: Eliminate warning messages for SRQ_LIMIT under SRIOV Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:00 +0200
[PATCH 4.4 092/101] x86/mm: Fix flush_tlb_page() on Xen Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:00 +0200
[PATCH 4.4 088/101] sched/loadavg: Avoid loadavg spikes caused by delayed NO_HZ accounting Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:00 +0200
[PATCH 4.4 072/101] arm64: assembler: make adr_l work in modules under KASLR Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:00 +0200
Re: [PATCH 4.4 072/101] arm64: assembler: make adr_l work in modules under KASLR Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-04 11:30 +0200
Re: [PATCH 4.4 072/101] arm64: assembler: make adr_l work in modules under KASLR Ard Biesheuvel <ard.biesheuvel@linaro.org> - 2017-07-04 11:30 +0200
[PATCH 4.4 083/101] jump label: fix passing kbuild_cflags when checking for asm goto support Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:00 +0200
[PATCH 4.4 084/101] xfrm: fix stack access out of bounds with CONFIG_XFRM_SUB_POLICY Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:00 +0200
[PATCH 4.4 078/101] be2net: fix status check in be_cmd_pmac_add() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:00 +0200
[PATCH 4.4 081/101] sctp: check af before verify address in sctp_addr_id2transport Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:00 +0200
[PATCH 4.4 039/101] net: korina: Fix NAPI versus resources freeing Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 067/101] ibmveth: Add a proper check for the availability of the checksum features Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 010/101] ipv6: fix calling in6_ifa_hold incorrectly for dad work Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 035/101] qla2xxx: Fix erroneous invalid handle message Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 024/101] MIPS: Fix IRQ tracing & lockdep when rescheduling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 018/101] netfilter: synproxy: fix conntrackd interaction Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 048/101] bgmac: Fix reversed test of build_skb() return value. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 015/101] ipv6: Do not leak throw route references Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 049/101] net: bgmac: Fix SOF bit checking Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 040/101] MIPS: ralink: MT7688 pinmux fixes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 042/101] MIPS: ralink: Fix invalid assignment of SoC type Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 026/101] ALSA: hda - set input_path bitmap to zero after moving it to new place Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 030/101] block: fix module reference leak on put_disk() call for cgroups throttle Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 071/101] spi: davinci: use dma_mapping_error() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
Re: [PATCH 4.4 071/101] spi: davinci: use dma_mapping_error() Ben Hutchings <ben.hutchings@codethink.co.uk> - 2017-07-05 16:30 +0200
[PATCH 4.4 029/101] sysctl: enable strict writes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 012/101] decnet: always not take dst->__refcnt when inserting dst into hash table Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 070/101] scsi: lpfc: avoid double free of resource identifiers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 074/101] x86/mpx: Use compatible types in comparison to fix sparse error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 025/101] ALSA: hda - Fix endless loop of codec configure Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 051/101] net: bgmac: Remove superflous netif_carrier_on() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 033/101] scsi: sd: Fix wrong DPOFUA disable in sd_read_cache_type Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 064/101] vfio/spapr: fail tce_iommu_attach_group() when iommu_data is null Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 068/101] kernel/panic.c: add missing \n Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 050/101] net: bgmac: Start transmit queue in bgmac_open Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 037/101] net: mvneta: Fix for_each_present_cpu usage Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 027/101] drm/vmwgfx: Free hash table allocated by cmdbuf managed res mgr Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 041/101] MIPS: ralink: fix USB frequency scaling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 017/101] netfilter: xt_TCPMSS: add more sanity tests on tcph->doff Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:10 +0200
[PATCH 4.4 003/101] decnet: dn_rtmsg: Improve input length sanitization in dnrmg_receive_user_skb Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:20 +0200
[PATCH 4.4 021/101] mm, swap_cgroup: reschedule when neeed in swap_cgroup_swapoff() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:20 +0200
[PATCH 4.4 005/101] af_unix: Add sockaddr length checks before accessing sa_family in bind and connect handlers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:20 +0200
[PATCH 4.4 002/101] net: dont call strlen on non-terminated string in dev_set_alias() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:20 +0200
[PATCH 4.4 006/101] Fix an intermittent pr_emerg warning about lo becoming free. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:20 +0200
[PATCH 4.4 004/101] net: Zero ifla_vf_info in rtnl_fill_vfinfo() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:20 +0200
[PATCH 4.4 011/101] net/mlx5: Wait for FW readiness before initializing command interface Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:20 +0200
[PATCH 4.4 020/101] drm/ast: Handle configuration without P2A bridge Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:20 +0200
[PATCH 4.4 007/101] net: caif: Fix a sleep-in-atomic bug in cfpkt_create_pfx Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-03 17:20 +0200
Re: [PATCH 4.4 000/101] 4.4.76-stable review Guenter Roeck <linux@roeck-us.net> - 2017-07-03 21:40 +0200
Re: [PATCH 4.4 000/101] 4.4.76-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-04 10:10 +0200
Re: [PATCH 4.4 000/101] 4.4.76-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-04 10:10 +0200
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