linux/include
Dmitry Monakhov 213116e53f jbd2: fix race between jbd2_journal_remove_checkpoint and ->j_commit_callback
commit 794446c694 upstream.

The following race is possible:

[kjournald2]                              other_task
jbd2_journal_commit_transaction()
  j_state = T_FINISHED;
  spin_unlock(&journal->j_list_lock);
                                         ->jbd2_journal_remove_checkpoint()
					   ->jbd2_journal_free_transaction();
					     ->kmem_cache_free(transaction)
  ->j_commit_callback(journal, transaction);
    -> USE_AFTER_FREE

WARNING: at lib/list_debug.c:62 __list_del_entry+0x1c0/0x250()
Hardware name:
list_del corruption. prev->next should be ffff88019a4ec198, but was 6b6b6b6b6b6b6b6b
Modules linked in: cpufreq_ondemand acpi_cpufreq freq_table mperf coretemp kvm_intel kvm crc32c_intel ghash_clmulni_intel microcode sg xhci_hcd button sd_mod crc_t10dif aesni_intel ablk_helper cryptd lrw aes_x86_64 xts gf128mul ahci libahci pata_acpi ata_generic dm_mirror dm_region_hash dm_log dm_mod
Pid: 16400, comm: jbd2/dm-1-8 Tainted: G        W    3.8.0-rc3+ #107
Call Trace:
 [<ffffffff8106fb0d>] warn_slowpath_common+0xad/0xf0
 [<ffffffff8106fc06>] warn_slowpath_fmt+0x46/0x50
 [<ffffffff813637e9>] ? ext4_journal_commit_callback+0x99/0xc0
 [<ffffffff8148cae0>] __list_del_entry+0x1c0/0x250
 [<ffffffff813637bf>] ext4_journal_commit_callback+0x6f/0xc0
 [<ffffffff813ca336>] jbd2_journal_commit_transaction+0x23a6/0x2570
 [<ffffffff8108aa42>] ? try_to_del_timer_sync+0x82/0xa0
 [<ffffffff8108b491>] ? del_timer_sync+0x91/0x1e0
 [<ffffffff813d3ecf>] kjournald2+0x19f/0x6a0
 [<ffffffff810ad630>] ? wake_up_bit+0x40/0x40
 [<ffffffff813d3d30>] ? bit_spin_lock+0x80/0x80
 [<ffffffff810ac6be>] kthread+0x10e/0x120
 [<ffffffff810ac5b0>] ? __init_kthread_worker+0x70/0x70
 [<ffffffff818ff6ac>] ret_from_fork+0x7c/0xb0
 [<ffffffff810ac5b0>] ? __init_kthread_worker+0x70/0x70

In order to demonstrace this issue one should mount ext4 with mount -o
discard option on SSD disk.  This makes callback longer and race
window becomes wider.

In order to fix this we should mark transaction as finished only after
callbacks have completed

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-07 19:51:57 -07:00
..
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-05-05 10:06:06 -07:00
asm-generic mm: allow arch code to control the user page table ceiling 2013-05-07 19:51:55 -07:00
crypto crypto: user - Fix lookup of algorithms with IV generator 2012-03-29 19:52:47 +08:00
drm drm/radeon: add Richland pci ids 2013-03-28 12:12:13 -07:00
keys
linux jbd2: fix race between jbd2_journal_remove_checkpoint and ->j_commit_callback 2013-05-07 19:51:57 -07:00
math-emu
media Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-05-14 11:23:37 -07:00
misc
mtd
net net: fix incorrect credentials passing 2013-05-01 09:41:16 -07:00
pcmcia
rdma infiniband: pass rdma_cm module to netlink_dump_start 2012-10-28 10:14:15 -07:00
rxrpc
scsi SCSI: libsas: fix taskfile corruption in sas_ata_qc_fill_rtf 2012-07-16 09:04:37 -07:00
sound ALSA: Add a reference counter to card instance 2012-11-17 13:16:13 -08:00
target target: Add link_magic for fabric allow_link destination target_items 2013-01-21 11:45:24 -08:00
trace xen/mmu: Use Xen specific TLB flush instead of the generic one. 2012-11-17 13:15:54 -08:00
video atmel_lcdfb: fix 16-bpp modes on older SOCs 2013-03-20 13:05:00 -07:00
xen xen/blkback: correctly respond to unknown, non-native requests 2013-04-05 10:04:18 -07:00
Kbuild