possible deadlock in ocfs2_lock_global_qf (3)

Status: upstream: reported on 2026/08/02 07:30
Reported-by: syzbot+193dbb8aeea8afc0ad13@syzkaller.appspotmail.com
First crash: 80d, last: 13d
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 possible deadlock in ocfs2_lock_global_qf (2) 4 1 201d 201d 0/3 auto-obsoleted due to no activity on 2026/07/12 07:37
linux-6.6 possible deadlock in ocfs2_lock_global_qf 4 1 453d 453d 0/2 auto-obsoleted due to no activity on 2025/11/01 13:37
upstream possible deadlock in ocfs2_lock_global_qf prio:normal ocfs2 4 syz, C 4068 156d 747d 0/29 auto-obsoleted due to no activity on 2026/07/26 21:55
linux-5.15 possible deadlock in ocfs2_lock_global_qf (2) 4 1 141d 141d 0/3 auto-obsoleted due to no activity on 2026/09/10 03:12
linux-5.15 possible deadlock in ocfs2_lock_global_qf origin:lts-only 4 syz, C done 303 234d 751d 0/3 auto-obsoleted due to no activity on 2026/05/09 18:33
linux-6.1 possible deadlock in ocfs2_lock_global_qf 4 264 285d 749d 0/3 auto-obsoleted due to no activity on 2026/03/20 02:14
linux-6.6 possible deadlock in ocfs2_lock_global_qf (2) 4 2 181d 241d 0/2 auto-obsoleted due to no activity on 2026/08/01 03:43

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.1379/8764 is trying to acquire lock:
ffff0000e1bd14a0 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_lock_global_qf+0x1ac/0x23c fs/ocfs2/quota_global.c:314

but task is already holding lock:
ffff0000e1bd1808 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:764 [inline]
ffff0000e1bd1808 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: ocfs2_lock_global_qf+0x190/0x23c fs/ocfs2/quota_global.c:313

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}:
       down_write+0x5c/0x88 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:764 [inline]
       ocfs2_lock_global_qf+0x190/0x23c fs/ocfs2/quota_global.c:313
       ocfs2_acquire_dquot+0x260/0xab0 fs/ocfs2/quota_global.c:816
       dqget+0x638/0xa98 fs/quota/dquot.c:1013
       __dquot_initialize+0x2e4/0xb30 fs/quota/dquot.c:1542
       dquot_initialize+0x24/0x34 fs/quota/dquot.c:1604
       ocfs2_get_init_inode+0x140/0x1b4 fs/ocfs2/namei.c:202
       ocfs2_mknod+0x7f8/0x212c fs/ocfs2/namei.c:311
       ocfs2_mkdir+0x19c/0x51c fs/ocfs2/namei.c:659
       vfs_mkdir+0x314/0x4d8 fs/namei.c:4157
       do_mkdirat+0x1b8/0x3ec fs/namei.c:4182
       __do_sys_mkdirat fs/namei.c:4197 [inline]
       __se_sys_mkdirat fs/namei.c:4195 [inline]
       __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4195
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
       do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
       el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

-> #4 (&dquot->dq_lock){+.+.}-{3:3}:
       __mutex_lock_common+0x1a0/0x1f3c kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
       dquot_commit+0x54/0x1c8 fs/quota/dquot.c:535
       ext4_write_dquot+0x1b4/0x320 fs/ext4/super.c:6817
       ext4_mark_dquot_dirty+0xe8/0x150 fs/ext4/super.c:6894
       mark_dquot_dirty fs/quota/dquot.c:400 [inline]
       mark_all_dquot_dirty+0x108/0x424 fs/quota/dquot.c:440
       __dquot_alloc_space+0x564/0xcfc fs/quota/dquot.c:1777
       dquot_alloc_space_nodirty include/linux/quotaops.h:293 [inline]
       dquot_alloc_space include/linux/quotaops.h:306 [inline]
       dquot_alloc_block include/linux/quotaops.h:330 [inline]
       ext4_mb_new_blocks+0xd40/0x4244 fs/ext4/mballoc.c:5740
       ext4_ext_map_blocks+0x1330/0x563c fs/ext4/extents.c:4361
       ext4_map_blocks+0x7b0/0x160c fs/ext4/inode.c:681
       ext4_getblk+0x178/0x680 fs/ext4/inode.c:892
       ext4_bread+0x3c/0x1a8 fs/ext4/inode.c:948
       ext4_append+0x23c/0x488 fs/ext4/namei.c:83
       ext4_init_new_dir+0x270/0x4f0 fs/ext4/namei.c:3032
       ext4_mkdir+0x3b8/0xa28 fs/ext4/namei.c:3078
       vfs_mkdir+0x314/0x4d8 fs/namei.c:4157
       do_mkdirat+0x1b8/0x3ec fs/namei.c:4182
       __do_sys_mkdirat fs/namei.c:4197 [inline]
       __se_sys_mkdirat fs/namei.c:4195 [inline]
       __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4195
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
       do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
       el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

-> #3 (&ei->i_data_sem){++++}-{3:3}:
       down_write+0x5c/0x88 kernel/locking/rwsem.c:1573
       ext4_map_blocks+0x720/0x160c fs/ext4/inode.c:674
       mpage_map_one_extent fs/ext4/inode.c:2436 [inline]
       mpage_map_and_submit_extent fs/ext4/inode.c:2489 [inline]
       ext4_writepages+0xdbc/0x28fc fs/ext4/inode.c:2857
       do_writepages+0x2c4/0x50c mm/page-writeback.c:2491
       __writeback_single_inode+0x164/0x157c fs/fs-writeback.c:1688
       writeback_sb_inodes+0x870/0x1470 fs/fs-writeback.c:1979
       __writeback_inodes_wb+0x104/0x370 fs/fs-writeback.c:2050
       wb_writeback+0x420/0xfdc fs/fs-writeback.c:2155
       wb_check_background_flush fs/fs-writeback.c:2221 [inline]
       wb_do_writeback fs/fs-writeback.c:2309 [inline]
       wb_workfn+0xb40/0xe18 fs/fs-writeback.c:2336
       process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292
       worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
       kthread+0x254/0x2e0 kernel/kthread.c:376
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850

-> #2 (jbd2_handle){++++}-{0:0}:
       jbd2_journal_lock_updates+0xa8/0x318 fs/jbd2/transaction.c:880
       __ocfs2_flush_truncate_log+0x268/0x10a4 fs/ocfs2/alloc.c:6029
       ocfs2_flush_truncate_log+0x4c/0x6c fs/ocfs2/alloc.c:6076
       ocfs2_sync_fs+0x100/0x2c0 fs/ocfs2/super.c:402
       sync_filesystem+0x1a0/0x218 fs/sync.c:66
       generic_shutdown_super+0x74/0x32c fs/super.c:474
       kill_block_super+0x78/0xe0 fs/super.c:1481
       deactivate_locked_super+0xb4/0x128 fs/super.c:332
       deactivate_super+0xe4/0x104 fs/super.c:363
       cleanup_mnt+0x3a8/0x430 fs/namespace.c:1191
       __cleanup_mnt+0x20/0x30 fs/namespace.c:1198
       task_work_run+0x1f4/0x280 kernel/task_work.c:203
       resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
       do_notify_resume+0x20f8/0x2c84 arch/arm64/kernel/signal.c:1151
       prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
       exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
       el0_svc+0x9c/0x12c arch/arm64/kernel/entry-common.c:638
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

-> #1 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}:
       down_write+0x5c/0x88 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:764 [inline]
       ocfs2_try_to_free_truncate_log+0xb4/0x2f4 fs/ocfs2/alloc.c:6124
       ocfs2_reserve_clusters_with_limit+0x3b4/0xa3c fs/ocfs2/suballoc.c:1202
       ocfs2_reserve_clusters fs/ocfs2/suballoc.c:1245 [inline]
       ocfs2_lock_allocators+0x270/0x530 fs/ocfs2/suballoc.c:2701
       ocfs2_extend_allocation+0x37c/0x1760 fs/ocfs2/file.c:585
       ocfs2_extend_no_holes+0x1a4/0x438 fs/ocfs2/file.c:1027
       ocfs2_expand_nonsparse_inode+0x134/0x3b0 fs/ocfs2/aops.c:1623
       ocfs2_write_begin_nolock+0xea4/0x3a80 fs/ocfs2/aops.c:1689
       ocfs2_write_begin+0x1b4/0x318 fs/ocfs2/aops.c:1906
       generic_perform_write+0x240/0x508 mm/filemap.c:3862
       __generic_file_write_iter+0x130/0x250 mm/filemap.c:3960
       ocfs2_file_write_iter+0x13ac/0x1cd0 fs/ocfs2/file.c:2469
       call_write_iter include/linux/fs.h:2271 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x3c8/0x7c8 fs/read_write.c:584
       ksys_pwrite64 fs/read_write.c:699 [inline]
       __do_sys_pwrite64 fs/read_write.c:709 [inline]
       __se_sys_pwrite64 fs/read_write.c:706 [inline]
       __arm64_sys_pwrite64+0x178/0x210 fs/read_write.c:706
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
       do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
       el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

-> #0 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3162 [inline]
       check_prevs_add kernel/locking/lockdep.c:3281 [inline]
       validate_chain kernel/locking/lockdep.c:3897 [inline]
       __lock_acquire+0x3504/0x7280 kernel/locking/lockdep.c:5171
       lock_acquire+0x210/0x63c kernel/locking/lockdep.c:5790
       down_write+0x5c/0x88 kernel/locking/rwsem.c:1573
       ocfs2_lock_global_qf+0x1ac/0x23c fs/ocfs2/quota_global.c:314
       ocfs2_acquire_dquot+0x260/0xab0 fs/ocfs2/quota_global.c:816
       dqget+0x638/0xa98 fs/quota/dquot.c:1013
       __dquot_initialize+0x2e4/0xb30 fs/quota/dquot.c:1542
       dquot_initialize+0x24/0x34 fs/quota/dquot.c:1604
       ocfs2_get_init_inode+0x140/0x1b4 fs/ocfs2/namei.c:202
       ocfs2_mknod+0x7f8/0x212c fs/ocfs2/namei.c:311
       ocfs2_mkdir+0x19c/0x51c fs/ocfs2/namei.c:659
       vfs_mkdir+0x314/0x4d8 fs/namei.c:4157
       do_mkdirat+0x1b8/0x3ec fs/namei.c:4182
       __do_sys_mkdirat fs/namei.c:4197 [inline]
       __se_sys_mkdirat fs/namei.c:4195 [inline]
       __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4195
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
       do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
       el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

other info that might help us debug this:

Chain exists of:
  &ocfs2_quota_ip_alloc_sem_key --> &dquot->dq_lock --> &ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7);
                               lock(&dquot->dq_lock);
                               lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7);
  lock(&ocfs2_quota_ip_alloc_sem_key);

 *** DEADLOCK ***

5 locks held by syz.0.1379/8764:
 #0: ffff0000cc0b0460 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:402
 #1: ffff0000fa03a648 (&type->i_mutex_dir_key#12/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:799 [inline]
 #1: ffff0000fa03a648 (&type->i_mutex_dir_key#12/1){+.+.}-{3:3}, at: filename_create+0x1b0/0x3a8 fs/namei.c:3927
 #2: ffff0000e1bd3488 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:764 [inline]
 #2: ffff0000e1bd3488 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x110/0x3d40 fs/ocfs2/suballoc.c:804
 #3: ffff0000fa39c0a8 (&dquot->dq_lock){+.+.}-{3:3}, at: ocfs2_acquire_dquot+0x254/0xab0 fs/ocfs2/quota_global.c:811
 #4: ffff0000e1bd1808 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:764 [inline]
 #4: ffff0000e1bd1808 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: ocfs2_lock_global_qf+0x190/0x23c fs/ocfs2/quota_global.c:313

stack backtrace:
CPU: 1 PID: 8764 Comm: syz.0.1379 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2088
 check_noncircular+0x290/0x370 kernel/locking/lockdep.c:2215
 check_prev_add kernel/locking/lockdep.c:3162 [inline]
 check_prevs_add kernel/locking/lockdep.c:3281 [inline]
 validate_chain kernel/locking/lockdep.c:3897 [inline]
 __lock_acquire+0x3504/0x7280 kernel/locking/lockdep.c:5171
 lock_acquire+0x210/0x63c kernel/locking/lockdep.c:5790
 down_write+0x5c/0x88 kernel/locking/rwsem.c:1573
 ocfs2_lock_global_qf+0x1ac/0x23c fs/ocfs2/quota_global.c:314
 ocfs2_acquire_dquot+0x260/0xab0 fs/ocfs2/quota_global.c:816
 dqget+0x638/0xa98 fs/quota/dquot.c:1013
 __dquot_initialize+0x2e4/0xb30 fs/quota/dquot.c:1542
 dquot_initialize+0x24/0x34 fs/quota/dquot.c:1604
 ocfs2_get_init_inode+0x140/0x1b4 fs/ocfs2/namei.c:202
 ocfs2_mknod+0x7f8/0x212c fs/ocfs2/namei.c:311
 ocfs2_mkdir+0x19c/0x51c fs/ocfs2/namei.c:659
 vfs_mkdir+0x314/0x4d8 fs/namei.c:4157
 do_mkdirat+0x1b8/0x3ec fs/namei.c:4182
 __do_sys_mkdirat fs/namei.c:4197 [inline]
 __se_sys_mkdirat fs/namei.c:4195 [inline]
 __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4195
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/07 10:13 linux-6.1.y a500ba24937a 6520ecdb .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_lock_global_qf
2026/09/08 14:25 linux-6.1.y cf82dcca9634 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_lock_global_qf
2026/08/16 01:00 linux-6.1.y e4f7d8be268e 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_lock_global_qf
2026/08/16 00:57 linux-6.1.y e4f7d8be268e 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_lock_global_qf
2026/08/02 07:29 linux-6.1.y fb28aa725e05 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_lock_global_qf
* Struck through repros no longer work on HEAD.