Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1212005
| From | Jiri Slaby <jslaby@suse.cz> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3.12 02/82] futex: Fix a race condition between REQUEUE_PI and task death |
| Date | 2015-08-24 11:40 +0200 |
| Message-ID | <q0Wop-3Lk-3@gated-at.bofh.it> (permalink) |
| References | <q0VVn-3cH-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Brian Silverman <bsilver16384@gmail.com>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit 30a6b8031fe14031ab27c1fa3483cb9780e7f63c upstream.
free_pi_state and exit_pi_state_list both clean up futex_pi_state's.
exit_pi_state_list takes the hb lock first, and most callers of
free_pi_state do too. requeue_pi doesn't, which means free_pi_state
can free the pi_state out from under exit_pi_state_list. For example:
task A | task B
exit_pi_state_list |
pi_state = |
curr->pi_state_list->next |
| futex_requeue(requeue_pi=1)
| // pi_state is the same as
| // the one in task A
| free_pi_state(pi_state)
| list_del_init(&pi_state->list)
| kfree(pi_state)
list_del_init(&pi_state->list) |
Move the free_pi_state calls in requeue_pi to before it drops the hb
locks which it's already holding.
[ tglx: Removed a pointless free_pi_state() call and the hb->lock held
debugging. The latter comes via a seperate patch ]
Signed-off-by: Brian Silverman <bsilver16384@gmail.com>
Cc: austin.linux@gmail.com
Cc: darren@dvhart.com
Cc: peterz@infradead.org
Cc: Mike Galbraith <mgalbraith@suse.de>
Link: http://lkml.kernel.org/r/1414282837-23092-1-git-send-email-bsilver16384@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
kernel/futex.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/kernel/futex.c b/kernel/futex.c
index e4b9b60e25b1..bd0bc06772f6 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -490,8 +490,14 @@ static struct futex_pi_state * alloc_pi_state(void)
return pi_state;
}
+/*
+ * Must be called with the hb lock held.
+ */
static void free_pi_state(struct futex_pi_state *pi_state)
{
+ if (!pi_state)
+ return;
+
if (!atomic_dec_and_test(&pi_state->refcount))
return;
@@ -1405,15 +1411,6 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags,
}
retry:
- if (pi_state != NULL) {
- /*
- * We will have to lookup the pi_state again, so free this one
- * to keep the accounting correct.
- */
- free_pi_state(pi_state);
- pi_state = NULL;
- }
-
ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1, VERIFY_READ);
if (unlikely(ret != 0))
goto out;
@@ -1501,6 +1498,8 @@ retry_private:
case 0:
break;
case -EFAULT:
+ free_pi_state(pi_state);
+ pi_state = NULL;
double_unlock_hb(hb1, hb2);
put_futex_key(&key2);
put_futex_key(&key1);
@@ -1510,6 +1509,8 @@ retry_private:
goto out;
case -EAGAIN:
/* The owner was exiting, try again. */
+ free_pi_state(pi_state);
+ pi_state = NULL;
double_unlock_hb(hb1, hb2);
put_futex_key(&key2);
put_futex_key(&key1);
@@ -1586,6 +1587,7 @@ retry_private:
}
out_unlock:
+ free_pi_state(pi_state);
double_unlock_hb(hb1, hb2);
/*
@@ -1602,8 +1604,6 @@ out_put_keys:
out_put_key1:
put_futex_key(&key1);
out:
- if (pi_state != NULL)
- free_pi_state(pi_state);
return ret ? ret : task_count;
}
--
2.5.0
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH 3.12 01/82] efi: fix 32bit kernel boot failed problem using efi Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:10 +0200
[PATCH 3.12 67/82] signalfd: fix information leak in signalfd_copyinfo Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 54/82] ipc: modify message queue accounting to not take kernel data structures into account Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 75/82] mm/hwpoison: fix page refcount of unknown non LRU page Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 64/82] x86/ldt: Correct LDT access in single stepping logic Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 44/82] ipmi: fix timeout calculation when bmc is disconnected Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 07/82] ARC: make sure instruction_pointer() returns unsigned value Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 59/82] x86/nmi/64: Switch stacks on userspace NMI entry Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 62/82] rcu: Move lockless_dereference() out of rcupdate.h Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 55/82] ocfs2: fix BUG in ocfs2_downconvert_thread_do_work() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 60/82] arch: Introduce smp_load_acquire(), smp_store_release() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 57/82] x86/nmi: Enable nested do_nmi() handling for 64-bit kernels Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 71/82] md/bitmap: return an error when bitmap superblock is corrupt. Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 76/82] xen-blkfront: don't add indirect pages to list when !feature_persistent Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 45/82] sparc64: Fix userspace FPU register corruptions. Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 74/82] ipc,sem: fix use after free on IPC_RMID after a task using same semaphore set exits Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 05/82] freeing unlinked file indefinitely delayed Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 66/82] x86/ldt: Further fix FPU emulation Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 69/82] signal: fix information leak in copy_siginfo_from_user32 Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 80/82] EDAC, ppc4xx: Access mci->csrows array elements properly Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 56/82] md/raid1: extend spinlock to protect raid1_end_read_request against inconsistencies Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 77/82] perf: Fix fasync handling on inherited events Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 63/82] x86/ldt: Make modify_ldt synchronous Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 82/82] rbd: fix copyup completion race Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 78/82] dm thin metadata: delete btrees when releasing metadata snapshot Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 73/82] ipc/sem.c: update/correct memory barriers Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 65/82] x86/ldt: Correct FPU emulation access to LDT Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 68/82] signal: fix information leak in copy_siginfo_to_user Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 81/82] drm/radeon: add new OLAND pci id Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 58/82] x86/nmi/64: Remove asm code that saves CR2 Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 79/82] localmodconfig: Use Kbuild files too Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 61/82] rcu: Provide counterpart to rcu_dereference() for non-RCU situations Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 72/82] mm, vmscan: Do not wait for page writeback for GFP_NOFS allocations Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 46/82] md: use kzalloc() when bitmap is disabled Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 70/82] path_openat(): fix double fput() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 39/82] ipr: Fix invalid array indexing for HRRQ Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 38/82] ipr: Fix incorrect trace indexing Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 51/82] ARM: OMAP2+: hwmod: Fix _wait_target_ready() for hwmods without sysc Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 32/82] ARM: realview: fix sparsemem build Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 31/82] hwrng: via-rng - Mark device ID table as __maybe_unused Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 10/82] ALSA: usb-audio: add dB range mapping for some devices Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 33/82] MIPS: Fix sched_getaffinity with MT FPAFF enabled Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 43/82] ima: extend "mask" policy matching support Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 41/82] USB: sierra: add 1199:68AB device ID Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 30/82] 3w-xxxx: fix mis-aligned struct accesses Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 40/82] xhci: fix off by one error in TRB DMA address boundary check Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 53/82] ALSA: hda - fix cs4210_spdif_automute() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 08/82] genirq: Prevent resend to interrupts marked IRQ_NESTED_THREAD Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 52/82] iscsi-target: Fix iscsit_start_kthreads failure OOPs Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 27/82] vhost: actually track log eventfd file Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 35/82] fsnotify: fix oops in fsnotify_clear_marks_by_group_flags() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 37/82] ipr: Fix locking for unit attention handling Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 36/82] drm/radeon/combios: add some validation of lvds values Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 47/82] ASoC: pcm1681: Fix setting de-emphasis sampling rate selection Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 50/82] crypto: ixp4xx - Remove bogus BUG_ON on scattered dst buffer Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 29/82] iscsi-target: Fix iser explicit logout TX kthread leak Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 48/82] x86/xen: Probe target addresses in set_aliased_prot() before the hypercall Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 49/82] xen/gntdevt: Fix race condition in gntdev_release() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
Re: [PATCH 3.12 49/82] xen/gntdevt: Fix race condition in gntdev_release() Luis Henriques <luis.henriques@canonical.com> - 2015-08-25 13:40 +0200
Re: [PATCH 3.12 49/82] xen/gntdevt: Fix race condition in gntdev_release() Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> - 2015-08-25 14:00 +0200
Re: [PATCH 3.12 49/82] xen/gntdevt: Fix race condition in gntdev_release() Jiri Slaby <jslaby@suse.cz> - 2015-08-25 15:20 +0200
Re: [PATCH 3.12 49/82] xen/gntdevt: Fix race condition in gntdev_release() Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> - 2015-08-25 16:10 +0200
Re: [PATCH 3.12 49/82] xen/gntdevt: Fix race condition in gntdev_release() Jiri Slaby <jslaby@suse.cz> - 2015-08-27 10:10 +0200
[PATCH 3.12 42/82] ima: add support for new "euid" policy condition Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 34/82] MIPS: Make set_pte() SMP safe. Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 02/82] futex: Fix a race condition between REQUEUE_PI and task death Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 28/82] iscsi-target: Fix use-after-free during TPG session shutdown Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 09/82] ALSA: usb-audio: Add MIDI support for Steinberg MI2/MI4 Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 15/82] mmc: sdhci-pxav3: fix platform_data is not initialized Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 19/82] blkcg: fix gendisk reference leak in blkg_conf_prep() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 26/82] rds: rds_ib_device.refcount overflow Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 23/82] xhci: report U3 when link is in resume state Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 03/82] HID: usbhid: add Chicony/Pixart usb optical mouse that needs QUIRK_ALWAYS_POLL Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 18/82] Input: usbtouchscreen - avoid unresponsive TSC-30 touch screen Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 25/82] xhci: do not report PLC when link is in internal resume state Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 22/82] xhci: Calculate old endpoints correctly on device reset Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 24/82] xhci: prevent bus_suspend if SS port resuming in phase 1 Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 06/82] s390/sclp: clear upper register halves in _sclp_print_early Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 17/82] tile: use free_bootmem_late() for initrd Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 04/82] mm: avoid setting up anonymous pages into file mapping Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 16/82] md/raid1: fix test for 'was read error from last working device'. Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 20/82] ata: pmp: add quirk for Marvell 4140 SATA PMP Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 11/82] ALSA: hda - Fix MacBook Pro 5,2 quirk Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 13/82] mac80211: clear subdir_stations when removing debugfs Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 21/82] usb-storage: ignore ZTE MF 823 card reader in mode 0x1225 Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 14/82] mmc: sdhci-esdhc: Make 8BIT bus work Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 12/82] st: null pointer dereference panic caused by use after kref_put by st_open Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
csiph-web