[v6.1] possible deadlock in __ocfs2_move_extents_range (2)
0 views
Skip to first unread message
syzbot
Jul 31, 2026, 2:07:44 AM (24 hours ago) Jul 31
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: fb28aa725e05 Linux 6.1.180
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=161178c6580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=8337a9f0ebc3b8df8f9d
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9a6fe2a54d0f/disk-fb28aa72.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/742b23a1d931/vmlinux-fb28aa72.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b3f257c16d2e/bzImage-fb28aa72.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8337a9...@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.261/5425 is trying to acquire lock:
ffff8880741389c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff8880741389c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:648 [inline]
ffff8880741389c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x1a31/0x3450 fs/ocfs2/move_extents.c:868
but task is already holding lock:
ffff8880740f89c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff8880740f89c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:640 [inline]
ffff8880740f89c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x131f/0x3450 fs/ocfs2/move_extents.c:868
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}:
down_write+0x36/0x60 kernel/locking/rwsem.c:1573
inode_lock include/linux/fs.h:758 [inline]
__ocfs2_flush_truncate_log+0x36a/0x1220 fs/ocfs2/alloc.c:6046
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]#6){+.+.}-{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_move_extent fs/ocfs2/move_extents.c:648 [inline]
__ocfs2_move_extents_range+0x1a31/0x3450 fs/ocfs2/move_extents.c:868
ocfs2_move_extents+0x409/0xa40 fs/ocfs2/move_extents.c:940
ocfs2_ioctl_move_extents+0x4d4/0x6e0 fs/ocfs2/move_extents.c:1066
ocfs2_ioctl+0x31d/0x7c0 fs/ocfs2/ioctl.c:946
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
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:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6);
*** DEADLOCK ***
5 locks held by syz.3.261/5425:
#0: ffff88807e87e460 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:446
#1: ffff888074139808 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#1: ffff888074139808 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: ocfs2_move_extents+0x19d/0xa40 fs/ocfs2/move_extents.c:918
#2: ffff8880741394a0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_move_extents+0x3fc/0xa40 fs/ocfs2/move_extents.c:938
#3: ffff8880740fa648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#3: ffff8880740fa648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x16a/0x4810 fs/ocfs2/suballoc.c:804
#4: ffff8880740f89c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#4: ffff8880740f89c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:640 [inline]
#4: ffff8880740f89c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x131f/0x3450 fs/ocfs2/move_extents.c:868
stack backtrace:
CPU: 0 PID: 5425 Comm: syz.3.261 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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_move_extent fs/ocfs2/move_extents.c:648 [inline]
__ocfs2_move_extents_range+0x1a31/0x3450 fs/ocfs2/move_extents.c:868
ocfs2_move_extents+0x409/0xa40 fs/ocfs2/move_extents.c:940
ocfs2_ioctl_move_extents+0x4d4/0x6e0 fs/ocfs2/move_extents.c:1066
ocfs2_ioctl+0x31d/0x7c0 fs/ocfs2/ioctl.c:946
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
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: 0033:0x7efcab79e019
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:00007efcac6bd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007efcaba26090 RCX: 00007efcab79e019
RDX: 00002000000000c0 RSI: 0000000040406f06 RDI: 0000000000000006
RBP: 00007efcab83500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efcaba26128 R14: 00007efcaba26090 R15: 00007ffc615d6e28
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: fb28aa725e05 Linux 6.1.180
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=161178c6580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=8337a9f0ebc3b8df8f9d
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9a6fe2a54d0f/disk-fb28aa72.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/742b23a1d931/vmlinux-fb28aa72.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b3f257c16d2e/bzImage-fb28aa72.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8337a9...@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.261/5425 is trying to acquire lock:
ffff8880741389c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff8880741389c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:648 [inline]
ffff8880741389c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x1a31/0x3450 fs/ocfs2/move_extents.c:868
but task is already holding lock:
ffff8880740f89c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff8880740f89c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:640 [inline]
ffff8880740f89c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x131f/0x3450 fs/ocfs2/move_extents.c:868
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}:
down_write+0x36/0x60 kernel/locking/rwsem.c:1573
inode_lock include/linux/fs.h:758 [inline]
__ocfs2_flush_truncate_log+0x36a/0x1220 fs/ocfs2/alloc.c:6046
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]#6){+.+.}-{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_move_extent fs/ocfs2/move_extents.c:648 [inline]
__ocfs2_move_extents_range+0x1a31/0x3450 fs/ocfs2/move_extents.c:868
ocfs2_move_extents+0x409/0xa40 fs/ocfs2/move_extents.c:940
ocfs2_ioctl_move_extents+0x4d4/0x6e0 fs/ocfs2/move_extents.c:1066
ocfs2_ioctl+0x31d/0x7c0 fs/ocfs2/ioctl.c:946
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
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:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6);
*** DEADLOCK ***
5 locks held by syz.3.261/5425:
#0: ffff88807e87e460 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:446
#1: ffff888074139808 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#1: ffff888074139808 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: ocfs2_move_extents+0x19d/0xa40 fs/ocfs2/move_extents.c:918
#2: ffff8880741394a0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_move_extents+0x3fc/0xa40 fs/ocfs2/move_extents.c:938
#3: ffff8880740fa648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#3: ffff8880740fa648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x16a/0x4810 fs/ocfs2/suballoc.c:804
#4: ffff8880740f89c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#4: ffff8880740f89c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:640 [inline]
#4: ffff8880740f89c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x131f/0x3450 fs/ocfs2/move_extents.c:868
stack backtrace:
CPU: 0 PID: 5425 Comm: syz.3.261 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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_move_extent fs/ocfs2/move_extents.c:648 [inline]
__ocfs2_move_extents_range+0x1a31/0x3450 fs/ocfs2/move_extents.c:868
ocfs2_move_extents+0x409/0xa40 fs/ocfs2/move_extents.c:940
ocfs2_ioctl_move_extents+0x4d4/0x6e0 fs/ocfs2/move_extents.c:1066
ocfs2_ioctl+0x31d/0x7c0 fs/ocfs2/ioctl.c:946
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
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: 0033:0x7efcab79e019
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:00007efcac6bd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007efcaba26090 RCX: 00007efcab79e019
RDX: 00002000000000c0 RSI: 0000000040406f06 RDI: 0000000000000006
RBP: 00007efcab83500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efcaba26128 R14: 00007efcaba26090 R15: 00007ffc615d6e28
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
Reply all
Reply to author
Forward
0 new messages