possible deadlock in ocfs2_remove_btree_range

Status: upstream: reported on 2026/01/29 20:10
Reported-by: syzbot+69c0df05e9a71a6ea62e@syzkaller.appspotmail.com
First crash: 213d, last: 14h16m
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in ocfs2_remove_btree_range (2) ocfs2 4 1 299d 295d 0/29 auto-obsoleted due to no activity on 2026/02/13 02:43
linux-5.15 possible deadlock in ocfs2_remove_btree_range (3) 4 2 17d 34d 0/3 upstream: reported on 2026/07/28 02:59
linux-5.15 possible deadlock in ocfs2_remove_btree_range (2) 4 4 139d 204d 0/3 auto-obsoleted due to no activity on 2026/07/23 14:33
linux-5.15 possible deadlock in ocfs2_remove_btree_range 4 1 715d 715d 0/3 auto-obsoleted due to no activity on 2024/12/24 02:14
upstream possible deadlock in ocfs2_remove_btree_range ocfs2 4 2 645d 672d 0/29 auto-obsoleted due to no activity on 2025/03/03 19:57

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.1192/8190 is trying to acquire lock:
ffff8880554fb488 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff8880554fb488 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: ocfs2_remove_btree_range+0x64f/0x15e0 fs/ocfs2/alloc.c:5742

but task is already holding lock:
ffff888055760660 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_truncate_file+0x365/0x1660 fs/ocfs2/file.c:467

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}:
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       ocfs2_lock_global_qf+0x1fe/0x290 fs/ocfs2/quota_global.c:314
       ocfs2_acquire_dquot+0x2b8/0xb80 fs/ocfs2/quota_global.c:816
       dqget+0x713/0xbb0 fs/quota/dquot.c:1013
       ocfs2_setattr+0x1025/0x1d90 fs/ocfs2/file.c:1233
       notify_change+0xca0/0xf90 fs/attr.c:499
       chown_common+0x489/0x640 fs/open.c:736
       vfs_fchown fs/open.c:804 [inline]
       ksys_fchown+0xe2/0x150 fs/open.c:815
       __do_sys_fchown fs/open.c:823 [inline]
       __se_sys_fchown fs/open.c:821 [inline]
       __x64_sys_fchown+0x76/0x80 fs/open.c:821
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #4 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#8){+.+.}-{3:3}:
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:758 [inline]
       ocfs2_lock_global_qf+0x1d7/0x290 fs/ocfs2/quota_global.c:313
       ocfs2_acquire_dquot+0x2b8/0xb80 fs/ocfs2/quota_global.c:816
       dqget+0x713/0xbb0 fs/quota/dquot.c:1013
       ocfs2_setattr+0x1025/0x1d90 fs/ocfs2/file.c:1233
       notify_change+0xca0/0xf90 fs/attr.c:499
       chown_common+0x489/0x640 fs/open.c:736
       vfs_fchown fs/open.c:804 [inline]
       ksys_fchown+0xe2/0x150 fs/open.c:815
       __do_sys_fchown fs/open.c:823 [inline]
       __se_sys_fchown fs/open.c:821 [inline]
       __x64_sys_fchown+0x76/0x80 fs/open.c:821
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #3 (&dquot->dq_lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747
       dquot_commit+0x5a/0x410 fs/quota/dquot.c:535
       ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6817
       mark_dquot_dirty fs/quota/dquot.c:400 [inline]
       mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:440
       __dquot_free_space+0x7f8/0xbc0 fs/quota/dquot.c:1967
       dquot_free_space_nodirty include/linux/quotaops.h:372 [inline]
       dquot_free_space include/linux/quotaops.h:377 [inline]
       dquot_free_block include/linux/quotaops.h:388 [inline]
       ext4_mb_clear_bb fs/ext4/mballoc.c:6153 [inline]
       ext4_free_blocks+0x1be5/0x26a0 fs/ext4/mballoc.c:6283
       ext4_remove_blocks fs/ext4/extents.c:2523 [inline]
       ext4_ext_rm_leaf fs/ext4/extents.c:2707 [inline]
       ext4_ext_remove_space+0x22ba/0x43d0 fs/ext4/extents.c:2955
       ext4_ext_truncate+0x213/0x370 fs/ext4/extents.c:4491
       ext4_truncate+0xa5b/0x12a0 fs/ext4/inode.c:4302
       ext4_setattr+0x120f/0x1bc0 fs/ext4/inode.c:5668
       notify_change+0xca0/0xf90 fs/attr.c:499
       do_truncate+0x1ac/0x240 fs/open.c:65
       handle_truncate fs/namei.c:3293 [inline]
       do_open fs/namei.c:3638 [inline]
       path_openat+0x2897/0x2f10 fs/namei.c:3791
       do_filp_open+0x1ee/0x420 fs/namei.c:3818
       do_sys_openat2+0x14b/0x4f0 fs/open.c:1320
       do_sys_open fs/open.c:1336 [inline]
       __do_sys_open fs/open.c:1344 [inline]
       __se_sys_open fs/open.c:1340 [inline]
       __x64_sys_open+0x11b/0x140 fs/open.c:1340
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #2 (&ei->i_data_sem){++++}-{3:3}:
       down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520
       ext4_map_blocks+0x338/0x1a90 fs/ext4/inode.c:606
       ext4_append+0x22d/0x560 fs/ext4/namei.c:75
       ext4_init_new_dir+0x2b8/0x550 fs/ext4/namei.c:3030
       ext4_mkdir+0x4c3/0xc90 fs/ext4/namei.c:3076
       vfs_mkdir+0x386/0x570 fs/namei.c:4114
       do_mkdirat+0x1d8/0x440 fs/namei.c:4139
       __do_sys_mkdir fs/namei.c:4159 [inline]
       __se_sys_mkdir fs/namei.c:4157 [inline]
       __x64_sys_mkdir+0x6a/0x80 fs/namei.c:4157
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (jbd2_handle){++++}-{0:0}:
       jbd2_journal_lock_updates+0xa8/0x390 fs/jbd2/transaction.c:880
       __ocfs2_flush_truncate_log+0x2cf/0x1220 fs/ocfs2/alloc.c:6029
       ocfs2_flush_truncate_log+0x4b/0x60 fs/ocfs2/alloc.c:6076
       ocfs2_sync_fs+0x119/0x330 fs/ocfs2/super.c:402
       sync_filesystem+0x1be/0x220 fs/sync.c:66
       generic_shutdown_super+0x6b/0x340 fs/super.c:474
       kill_block_super+0x7c/0xe0 fs/super.c:1470
       deactivate_locked_super+0x93/0xf0 fs/super.c:332
       cleanup_mnt+0x471/0x4f0 fs/namespace.c:1191
       task_work_run+0x1d0/0x260 kernel/task_work.c:203
       resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
       exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
       exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
       __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
       syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
       do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{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+0x2d18/0x7c40 kernel/locking/lockdep.c:5063
       lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:758 [inline]
       ocfs2_remove_btree_range+0x64f/0x15e0 fs/ocfs2/alloc.c:5742
       ocfs2_commit_truncate+0xba2/0x1e00 fs/ocfs2/alloc.c:7353
       ocfs2_truncate_file+0xdf0/0x1660 fs/ocfs2/file.c:505
       ocfs2_setattr+0x16f8/0x1d90 fs/ocfs2/file.c:1212
       notify_change+0xca0/0xf90 fs/attr.c:499
       do_truncate+0x1ac/0x240 fs/open.c:65
       vfs_truncate+0x262/0x2f0 fs/open.c:111
       do_sys_truncate+0xf2/0x1c0 fs/open.c:134
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  &ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5 --> &ocfs2_sysfile_lock_key[args->fi_sysfile_type]#8 --> &ocfs2_quota_ip_alloc_sem_key

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_quota_ip_alloc_sem_key);
                               lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#8);
                               lock(&ocfs2_quota_ip_alloc_sem_key);
  lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5);

 *** DEADLOCK ***

3 locks held by syz.0.1192/8190:
 #0: ffff88807d0bc460 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402
 #1: ffff8880557609c8 (&sb->s_type->i_mutex_key#38){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff8880557609c8 (&sb->s_type->i_mutex_key#38){+.+.}-{3:3}, at: do_truncate+0x198/0x240 fs/open.c:63
 #2: ffff888055760660 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_truncate_file+0x365/0x1660 fs/ocfs2/file.c:467

stack backtrace:
CPU: 1 PID: 8190 Comm: syz.0.1192 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 check_noncircular+0x296/0x330 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+0x2d18/0x7c40 kernel/locking/lockdep.c:5063
 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676
 down_write+0x36/0x60 kernel/locking/rwsem.c:1573
 inode_lock include/linux/fs.h:758 [inline]
 ocfs2_remove_btree_range+0x64f/0x15e0 fs/ocfs2/alloc.c:5742
 ocfs2_commit_truncate+0xba2/0x1e00 fs/ocfs2/alloc.c:7353
 ocfs2_truncate_file+0xdf0/0x1660 fs/ocfs2/file.c:505
 ocfs2_setattr+0x16f8/0x1d90 fs/ocfs2/file.c:1212
 notify_change+0xca0/0xf90 fs/attr.c:499
 do_truncate+0x1ac/0x240 fs/open.c:65
 vfs_truncate+0x262/0x2f0 fs/open.c:111
 do_sys_truncate+0xf2/0x1c0 fs/open.c:134
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3ef1d9de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3ef2c47028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007f3ef2026090 RCX: 00007f3ef1d9de99
RDX: 0000000000000000 RSI: 00000000000042dc RDI: 00002000000001c0
RBP: 00007f3ef1e33eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3ef2026128 R14: 00007f3ef2026090 R15: 00007ffc5c05fe78
 </TASK>

Crashes (21):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/28 04:17 linux-6.1.y dc5c83b7f5f8 45ae1df4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in ocfs2_remove_btree_range
2026/04/15 16:08 linux-6.1.y 8e8fc038cad5 c441f497 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in ocfs2_remove_btree_range
2026/03/12 21:01 linux-6.1.y f2ddafa93a25 4efadf07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in ocfs2_remove_btree_range
2026/02/07 22:19 linux-6.1.y 0182cb5b74ee 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in ocfs2_remove_btree_range
2026/02/06 07:08 linux-6.1.y cd9b81672742 f03c4191 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in ocfs2_remove_btree_range
2026/08/31 02:37 linux-6.1.y d64a499eea6b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/08/18 19:16 linux-6.1.y e4f7d8be268e 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/08/08 13:14 linux-6.1.y e4f7d8be268e 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/08/08 13:09 linux-6.1.y e4f7d8be268e 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/08/08 13:06 linux-6.1.y e4f7d8be268e 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/08/06 20:34 linux-6.1.y 03f3a99e8e93 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/06/03 17:00 linux-6.1.y 228da13e907e 234057e5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/05/29 20:45 linux-6.1.y dcbcab9d7079 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/04/04 10:43 linux-6.1.y 1989cd3d56e2 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/03/06 17:25 linux-6.1.y f2ddafa93a25 41d8037d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/03/02 15:35 linux-6.1.y 779f9571ac3e b9dd6534 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/02/21 19:54 linux-6.1.y 779f9571ac3e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/02/10 13:38 linux-6.1.y 0182cb5b74ee 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/02/07 14:14 linux-6.1.y 0182cb5b74ee f20fc9f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/02/05 11:14 linux-6.1.y cd9b81672742 4936e85c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
2026/01/29 20:10 linux-6.1.y cd9b81672742 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_remove_btree_range
* Struck through repros no longer work on HEAD.