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| Kernel | Title | Repro | Cause bisect | Fix bisect | Count | Last | Reported | Patched | Status |
|---|---|---|---|---|---|---|---|---|---|
| linux-6.1 | possible deadlock in dqget | 1 | 144d | 144d | 0/3 | auto-obsoleted due to no activity on 2025/05/07 22:20 | |||
| upstream | possible deadlock in dqget ext4 ocfs2 | C | error | 62313 | now | 262d | 0/29 | upstream: reported C repro on 2024/10/01 08:09 |
ext4 filesystem being mounted at /312/file1 supports timestamps until 2038-01-19 (0x7fffffff)
======================================================
WARNING: possible circular locking dependency detected
6.6.94-syzkaller #0 Not tainted
------------------------------------------------------
syz.4.8379/25215 is trying to acquire lock:
ffff888077ff0ea8 (&dquot->dq_lock){+.+.}-{3:3}, at: wait_on_dquot fs/quota/dquot.c:356 [inline]
ffff888077ff0ea8 (&dquot->dq_lock){+.+.}-{3:3}, at: dqget+0x6fc/0xeb0 fs/quota/dquot.c:983
but task is already holding lock:
ffff888058cf8ac8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_setattr+0x86b/0x1c90 fs/ext4/inode.c:5470
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #5 (&ei->xattr_sem){++++}-{3:3}:
down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520
ext4_setattr+0x86b/0x1c90 fs/ext4/inode.c:5470
notify_change+0xb0d/0xe10 fs/attr.c:499
chown_common+0x3f9/0x5a0 fs/open.c:783
do_fchownat+0x168/0x270 fs/open.c:814
__do_sys_chown fs/open.c:834 [inline]
__se_sys_chown fs/open.c:832 [inline]
__x64_sys_chown+0x82/0x90 fs/open.c:832
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
-> #4 (jbd2_handle){++++}-{0:0}:
start_this_handle+0x1e9d/0x20c0 fs/jbd2/transaction.c:448
jbd2__journal_start+0x2bb/0x5b0 fs/jbd2/transaction.c:505
jbd2_journal_start+0x2a/0x40 fs/jbd2/transaction.c:544
ocfs2_start_trans+0x376/0x6c0 fs/ocfs2/journal.c:374
ocfs2_modify_bh+0xe9/0x470 fs/ocfs2/quota_local.c:101
ocfs2_local_read_info+0x13fd/0x1770 fs/ocfs2/quota_local.c:764
dquot_load_quota_sb+0x757/0xb80 fs/quota/dquot.c:2468
dquot_load_quota_inode+0x2dc/0x5d0 fs/quota/dquot.c:2505
ocfs2_enable_quotas+0x1c7/0x440 fs/ocfs2/super.c:926
ocfs2_fill_super+0x3f6d/0x4d90 fs/ocfs2/super.c:1141
mount_bdev+0x22b/0x2d0 fs/super.c:1643
legacy_get_tree+0xea/0x180 fs/fs_context.c:662
vfs_get_tree+0x8c/0x280 fs/super.c:1764
do_new_mount+0x24b/0xa40 fs/namespace.c:3366
do_mount fs/namespace.c:3706 [inline]
__do_sys_mount fs/namespace.c:3915 [inline]
__se_sys_mount+0x2da/0x3c0 fs/namespace.c:3892
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 (&journal->j_trans_barrier){.+.+}-{3:3}:
down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520
ocfs2_start_trans+0x36a/0x6c0 fs/ocfs2/journal.c:372
ocfs2_modify_bh+0xe9/0x470 fs/ocfs2/quota_local.c:101
ocfs2_local_read_info+0x13fd/0x1770 fs/ocfs2/quota_local.c:764
dquot_load_quota_sb+0x757/0xb80 fs/quota/dquot.c:2468
dquot_load_quota_inode+0x2dc/0x5d0 fs/quota/dquot.c:2505
ocfs2_enable_quotas+0x1c7/0x440 fs/ocfs2/super.c:926
ocfs2_fill_super+0x3f6d/0x4d90 fs/ocfs2/super.c:1141
mount_bdev+0x22b/0x2d0 fs/super.c:1643
legacy_get_tree+0xea/0x180 fs/fs_context.c:662
vfs_get_tree+0x8c/0x280 fs/super.c:1764
do_new_mount+0x24b/0xa40 fs/namespace.c:3366
do_mount fs/namespace.c:3706 [inline]
__do_sys_mount fs/namespace.c:3915 [inline]
__se_sys_mount+0x2da/0x3c0 fs/namespace.c:3892
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 (sb_internal#2){.+.+}-{0:0}:
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1633 [inline]
sb_start_intwrite include/linux/fs.h:1755 [inline]
ocfs2_start_trans+0x26b/0x6c0 fs/ocfs2/journal.c:370
ocfs2_acquire_dquot+0x67b/0xaf0 fs/ocfs2/quota_global.c:848
dqget+0x77c/0xeb0 fs/quota/dquot.c:988
dquot_set_dqblk+0x2b/0xf90 fs/quota/dquot.c:2831
quota_setquota+0x4b0/0x530 fs/quota/quota.c:310
__do_sys_quotactl fs/quota/quota.c:961 [inline]
__se_sys_quotactl+0x27b/0x950 fs/quota/quota.c:917
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_quota_ip_alloc_sem_key){++++}-{3:3}:
down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
ocfs2_create_local_dquot+0x1a4/0x1790 fs/ocfs2/quota_local.c:1224
ocfs2_acquire_dquot+0x7cf/0xaf0 fs/ocfs2/quota_global.c:871
dqget+0x77c/0xeb0 fs/quota/dquot.c:988
dquot_set_dqblk+0x2b/0xf90 fs/quota/dquot.c:2831
quota_setquota+0x4b0/0x530 fs/quota/quota.c:310
__do_sys_quotactl fs/quota/quota.c:961 [inline]
__se_sys_quotactl+0x27b/0x950 fs/quota/quota.c:917
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 (&dquot->dq_lock){+.+.}-{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
__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_transfer+0x2f9/0x6d0 fs/quota/dquot.c:2149
ext4_setattr+0x87d/0x1c90 fs/ext4/inode.c:5471
notify_change+0xb0d/0xe10 fs/attr.c:499
chown_common+0x3f9/0x5a0 fs/open.c:783
do_fchownat+0x168/0x270 fs/open.c:814
__do_sys_lchown fs/open.c:839 [inline]
__se_sys_lchown fs/open.c:837 [inline]
__x64_sys_lchown+0x85/0x90 fs/open.c:837
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:
&dquot->dq_lock --> jbd2_handle --> &ei->xattr_sem
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(&ei->xattr_sem);
lock(jbd2_handle);
lock(&ei->xattr_sem);
lock(&dquot->dq_lock);
*** DEADLOCK ***
3 locks held by syz.4.8379/25215:
#0: ffff8880571e6418 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:403
#1: ffff888058cf8e10 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#1: ffff888058cf8e10 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: chown_common+0x313/0x5a0 fs/open.c:773
#2: ffff888058cf8ac8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_setattr+0x86b/0x1c90 fs/ext4/inode.c:5470
stack backtrace:
CPU: 1 PID: 25215 Comm: syz.4.8379 Not tainted 6.6.94-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
__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_transfer+0x2f9/0x6d0 fs/quota/dquot.c:2149
ext4_setattr+0x87d/0x1c90 fs/ext4/inode.c:5471
notify_change+0xb0d/0xe10 fs/attr.c:499
chown_common+0x3f9/0x5a0 fs/open.c:783
do_fchownat+0x168/0x270 fs/open.c:814
__do_sys_lchown fs/open.c:839 [inline]
__se_sys_lchown fs/open.c:837 [inline]
__x64_sys_lchown+0x85/0x90 fs/open.c:837
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: 0033:0x7ff81c78e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff81d648038 EFLAGS: 00000246 ORIG_RAX: 000000000000005e
RAX: ffffffffffffffda RBX: 00007ff81c9b5fa0 RCX: 00007ff81c78e929
RDX: 0000000000000000 RSI: 000000000000ee01 RDI: 0000200000000000
RBP: 00007ff81c810b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff81c9b5fa0 R15: 00007ffd5a52fe18
</TASK>
| Time | Kernel | Commit | Syzkaller | Config | Log | Report | Syz repro | C repro | VM info | Assets (help?) | Manager | Title |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025/06/20 12:36 | linux-6.6.y | 6282921b6825 | 804b3919 | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci2-linux-6-6-kasan | possible deadlock in dqget |