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: 21h03m, last: 21h03m
▶ ▼ 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 121d 121d 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 374d 374d 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 77d 668d 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 62d 62d 0/3 upstream: reported on 2026/06/02 03:12
linux-5.15 possible deadlock in ocfs2_lock_global_qf origin:lts-only 4 syz, C done 303 155d 672d 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 206d 670d 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 102d 161d 0/2 auto-obsoleted due to no activity on 2026/08/01 03:43

Sample crash report:
JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,3) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.261/5728 is trying to acquire lock:
ffff0001000ea2e0 (&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:
ffff0001000ea648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff0001000ea648 (&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:758 [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+0x7d4/0x218c fs/ocfs2/namei.c:310
       ocfs2_mkdir+0x19c/0x51c fs/ocfs2/namei.c:657
       vfs_mkdir+0x314/0x4d8 fs/namei.c:4114
       do_mkdirat+0x1b8/0x3ec fs/namei.c:4139
       __do_sys_mkdirat fs/namei.c:4154 [inline]
       __se_sys_mkdirat fs/namei.c:4152 [inline]
       __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152
       __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+0x58/0x128 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:3030
       ext4_mkdir+0x3b8/0xa28 fs/ext4/namei.c:3076
       vfs_mkdir+0x314/0x4d8 fs/namei.c:4114
       do_mkdirat+0x1b8/0x3ec fs/namei.c:4139
       __do_sys_mkdirat fs/namei.c:4154 [inline]
       __se_sys_mkdirat fs/namei.c:4152 [inline]
       __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152
       __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+0x58/0x128 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:1673
       writeback_sb_inodes+0x870/0x1470 fs/fs-writeback.c:1964
       __writeback_inodes_wb+0x104/0x370 fs/fs-writeback.c:2035
       wb_writeback+0x420/0xfdc fs/fs-writeback.c:2140
       wb_check_background_flush fs/fs-writeback.c:2206 [inline]
       wb_do_writeback fs/fs-writeback.c:2294 [inline]
       wb_workfn+0xb40/0xe18 fs/fs-writeback.c:2321
       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 fs/ocfs2/alloc.c:6076 [inline]
       ocfs2_truncate_log_worker+0xa4/0x1a4 fs/ocfs2/alloc.c:6089
       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

-> #1 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}:
       down_write+0x5c/0x88 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:758 [inline]
       ocfs2_remove_btree_range+0x56c/0x12e8 fs/ocfs2/alloc.c:5742
       ocfs2_commit_truncate+0x880/0x1980 fs/ocfs2/alloc.c:7353
       ocfs2_truncate_file+0xc04/0x14dc fs/ocfs2/file.c:505
       ocfs2_setattr+0x12a0/0x1950 fs/ocfs2/file.c:1212
       notify_change+0xb5c/0xe20 fs/attr.c:499
       do_truncate+0x188/0x20c fs/open.c:65
       vfs_truncate+0x23c/0x2b0 fs/open.c:111
       do_sys_truncate+0xec/0x1b4 fs/open.c:134
       __do_sys_truncate fs/open.c:146 [inline]
       __se_sys_truncate fs/open.c:144 [inline]
       __arm64_sys_truncate+0x5c/0x70 fs/open.c:144
       __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+0x58/0x128 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:3095 [inline]
       check_prevs_add kernel/locking/lockdep.c:3214 [inline]
       validate_chain kernel/locking/lockdep.c:3830 [inline]
       __lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063
       lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676
       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+0x7d4/0x218c fs/ocfs2/namei.c:310
       ocfs2_mkdir+0x19c/0x51c fs/ocfs2/namei.c:657
       vfs_mkdir+0x314/0x4d8 fs/namei.c:4114
       do_mkdirat+0x1b8/0x3ec fs/namei.c:4139
       __do_sys_mkdirat fs/namei.c:4154 [inline]
       __se_sys_mkdirat fs/namei.c:4152 [inline]
       __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152
       __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+0x58/0x128 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.3.261/5728:
 #0: ffff0000cb7a4460 (sb_writers#31){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:402
 #1: ffff0001000fc2c8 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
 #1: ffff0001000fc2c8 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: filename_create+0x1b0/0x3a8 fs/namei.c:3884
 #2: ffff0001000edf48 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #2: ffff0001000edf48 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x110/0x3d40 fs/ocfs2/suballoc.c:804
 #3: ffff00010005a0a8 (&dquot->dq_lock){+.+.}-{3:3}, at: ocfs2_acquire_dquot+0x254/0xab0 fs/ocfs2/quota_global.c:811
 #4: ffff0001000ea648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #4: ffff0001000ea648 (&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: 5728 Comm: syz.3.261 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
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:2048
 check_noncircular+0x264/0x2f8 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3095 [inline]
 check_prevs_add kernel/locking/lockdep.c:3214 [inline]
 validate_chain kernel/locking/lockdep.c:3830 [inline]
 __lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063
 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676
 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+0x7d4/0x218c fs/ocfs2/namei.c:310
 ocfs2_mkdir+0x19c/0x51c fs/ocfs2/namei.c:657
 vfs_mkdir+0x314/0x4d8 fs/namei.c:4114
 do_mkdirat+0x1b8/0x3ec fs/namei.c:4139
 __do_sys_mkdirat fs/namei.c:4154 [inline]
 __se_sys_mkdirat fs/namei.c:4152 [inline]
 __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152
 __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+0x58/0x128 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 (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.