syzbot


possible deadlock in ocfs2_lock_global_qf

Status: upstream: reported on 2025/07/24 13:37
Reported-by: syzbot+f6a2ab483303c388d17d@syzkaller.appspotmail.com
First crash: 26d, last: 26d
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in ocfs2_lock_global_qf ocfs2 4 2861 5d00h 320d 0/29 upstream: reported on 2024/10/03 18:26
linux-5.15 possible deadlock in ocfs2_lock_global_qf origin:lts-only 4 C done 259 23h29m 324d 0/3 upstream: reported C repro on 2024/09/29 22:07
linux-6.1 possible deadlock in ocfs2_lock_global_qf 4 192 21h14m 323d 0/3 upstream: reported on 2024/10/01 11:31

Sample crash report:
(syz.4.2996,14914,0):ocfs2_block_check_validate:402 ERROR: CRC32 failed: stored: 0xb3775c19, computed 0x2dd1c265. Applying ECC.
JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,4) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.6.100-syzkaller #0 Not tainted
------------------------------------------------------
syz.4.2996/14914 is trying to acquire lock:
ffff88805e18b120 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_lock_global_qf+0x1e9/0x270 fs/ocfs2/quota_global.c:314

but task is already holding lock:
ffff88805e18b498 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
ffff88805e18b498 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: ocfs2_lock_global_qf+0x1cb/0x270 fs/ocfs2/quota_global.c:313

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}:
       down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:804 [inline]
       ocfs2_lock_global_qf+0x1cb/0x270 fs/ocfs2/quota_global.c:313
       ocfs2_acquire_dquot+0x2a1/0xaf0 fs/ocfs2/quota_global.c:816
       dqget+0x77c/0xeb0 fs/quota/dquot.c:988
       __dquot_initialize+0x3ba/0xcb0 fs/quota/dquot.c:1516
       ocfs2_get_init_inode+0x13c/0x1b0 fs/ocfs2/namei.c:202
       ocfs2_mknod+0x867/0x20f0 fs/ocfs2/namei.c:310
       ocfs2_mkdir+0x196/0x410 fs/ocfs2/namei.c:657
       vfs_mkdir+0x296/0x440 fs/namei.c:4113
       do_mkdirat+0x1d4/0x440 fs/namei.c:4136
       __do_sys_mkdirat fs/namei.c:4151 [inline]
       __se_sys_mkdirat fs/namei.c:4149 [inline]
       __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4149
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #3 (&dquot->dq_lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747
       wait_on_dquot fs/quota/dquot.c:356 [inline]
       dqget+0x6fc/0xeb0 fs/quota/dquot.c:983
       __dquot_initialize+0x3ba/0xcb0 fs/quota/dquot.c:1516
       ocfs2_get_init_inode+0x13c/0x1b0 fs/ocfs2/namei.c:202
       ocfs2_mknod+0x867/0x20f0 fs/ocfs2/namei.c:310
       ocfs2_mkdir+0x196/0x410 fs/ocfs2/namei.c:657
       vfs_mkdir+0x296/0x440 fs/namei.c:4113
       do_mkdirat+0x1d4/0x440 fs/namei.c:4136
       __do_sys_mkdirat fs/namei.c:4151 [inline]
       __se_sys_mkdirat fs/namei.c:4149 [inline]
       __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4149
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #2 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}:
       down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:804 [inline]
       ocfs2_remove_inode fs/ocfs2/inode.c:655 [inline]
       ocfs2_wipe_inode fs/ocfs2/inode.c:818 [inline]
       ocfs2_delete_inode fs/ocfs2/inode.c:1079 [inline]
       ocfs2_evict_inode+0x1313/0x3e60 fs/ocfs2/inode.c:1216
       evict+0x486/0x870 fs/inode.c:705
       d_delete_notify include/linux/fsnotify.h:269 [inline]
       vfs_rmdir+0x39b/0x4d0 fs/namei.c:4209
       do_rmdir+0x29e/0x5c0 fs/namei.c:4255
       __do_sys_rmdir fs/namei.c:4274 [inline]
       __se_sys_rmdir fs/namei.c:4272 [inline]
       __x64_sys_rmdir+0x49/0x50 fs/namei.c:4272
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]){+.+.}-{3:3}:
       down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:804 [inline]
       ocfs2_del_inode_from_orphan+0x135/0x740 fs/ocfs2/namei.c:2716
       ocfs2_dio_end_io_write fs/ocfs2/aops.c:2333 [inline]
       ocfs2_dio_end_io+0x47b/0x10f0 fs/ocfs2/aops.c:2431
       dio_complete+0x254/0x710 fs/direct-io.c:282
       __blockdev_direct_IO+0x2dc8/0x3420 fs/direct-io.c:1308
       ocfs2_direct_IO+0x240/0x2b0 fs/ocfs2/aops.c:2468
       generic_file_direct_write+0x1d4/0x3e0 mm/filemap.c:3941
       __generic_file_write_iter+0x11b/0x230 mm/filemap.c:4097
       ocfs2_file_write_iter+0x1582/0x1d00 fs/ocfs2/file.c:2468
       do_iter_readv_writev fs/read_write.c:-1 [inline]
       do_iter_write+0x79a/0xc70 fs/read_write.c:860
       iter_file_splice_write+0x66f/0xc50 fs/splice.c:736
       do_splice_from fs/splice.c:933 [inline]
       direct_splice_actor+0xe8/0x130 fs/splice.c:1142
       splice_direct_to_actor+0x2f0/0x870 fs/splice.c:1088
       do_splice_direct+0x1b7/0x2c0 fs/splice.c:1194
       do_sendfile+0x5dc/0xf70 fs/read_write.c:1254
       __do_sys_sendfile64 fs/read_write.c:1322 [inline]
       __se_sys_sendfile64+0x13f/0x190 fs/read_write.c:1308
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
       lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
       down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
       ocfs2_lock_global_qf+0x1e9/0x270 fs/ocfs2/quota_global.c:314
       ocfs2_acquire_dquot+0x2a1/0xaf0 fs/ocfs2/quota_global.c:816
       dqget+0x77c/0xeb0 fs/quota/dquot.c:988
       __dquot_initialize+0x3ba/0xcb0 fs/quota/dquot.c:1516
       ocfs2_get_init_inode+0x13c/0x1b0 fs/ocfs2/namei.c:202
       ocfs2_mknod+0x867/0x20f0 fs/ocfs2/namei.c:310
       ocfs2_mkdir+0x196/0x410 fs/ocfs2/namei.c:657
       vfs_mkdir+0x296/0x440 fs/namei.c:4113
       do_mkdirat+0x1d4/0x440 fs/namei.c:4136
       __do_sys_mkdirat fs/namei.c:4151 [inline]
       __se_sys_mkdirat fs/namei.c:4149 [inline]
       __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4149
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

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.4.2996/14914:
 #0: ffff88805810e418 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:403
 #1: ffff88805e249818 (&type->i_mutex_dir_key#10/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
 #1: ffff88805e249818 (&type->i_mutex_dir_key#10/1){+.+.}-{3:3}, at: filename_create+0x1f6/0x460 fs/namei.c:3882
 #2: ffff88805e1ea658 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #2: ffff88805e1ea658 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x165/0x4360 fs/ocfs2/suballoc.c:782
 #3: ffff88804f30e0a8 (&dquot->dq_lock){+.+.}-{3:3}, at: ocfs2_acquire_dquot+0x294/0xaf0 fs/ocfs2/quota_global.c:811
 #4: ffff88805e18b498 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #4: ffff88805e18b498 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#7){+.+.}-{3:3}, at: ocfs2_lock_global_qf+0x1cb/0x270 fs/ocfs2/quota_global.c:313

stack backtrace:
CPU: 1 PID: 14914 Comm: syz.4.2996 Not tainted 6.6.100-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 check_noncircular+0x2bd/0x3c0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
 ocfs2_lock_global_qf+0x1e9/0x270 fs/ocfs2/quota_global.c:314
 ocfs2_acquire_dquot+0x2a1/0xaf0 fs/ocfs2/quota_global.c:816
 dqget+0x77c/0xeb0 fs/quota/dquot.c:988
 __dquot_initialize+0x3ba/0xcb0 fs/quota/dquot.c:1516
 ocfs2_get_init_inode+0x13c/0x1b0 fs/ocfs2/namei.c:202
 ocfs2_mknod+0x867/0x20f0 fs/ocfs2/namei.c:310
 ocfs2_mkdir+0x196/0x410 fs/ocfs2/namei.c:657
 vfs_mkdir+0x296/0x440 fs/namei.c:4113
 do_mkdirat+0x1d4/0x440 fs/namei.c:4136
 __do_sys_mkdirat fs/namei.c:4151 [inline]
 __se_sys_mkdirat fs/namei.c:4149 [inline]
 __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4149
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8151f8d217
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8152d57e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f8152d57ef0 RCX: 00007f8151f8d217
RDX: 00000000000001ff RSI: 0000200000000680 RDI: 00000000ffffff9c
RBP: 0000200000000080 R08: 0000200000000d40 R09: 0000000000000000
R10: 0000200000000080 R11: 0000000000000246 R12: 0000200000000680
R13: 00007f8152d57eb0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/24 13:37 linux-6.6.y dbcb8d8e4163 65d60d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in ocfs2_lock_global_qf
* Struck through repros no longer work on HEAD.