[v6.6] possible deadlock in __ocfs2_move_extents_range
2 views
Skip to first unread message
syzbot
Jun 27, 2025, 7:37:30 PM6/27/25
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 3f5b4c104b7d Linux 6.6.95
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=123c108c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b80883c3ded77c16
dashboard link: https://syzkaller.appspot.com/bug?extid=e8625e4e646b849e721a
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0efd4e01816e/disk-3f5b4c10.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f7c9d20858cc/vmlinux-3f5b4c10.xz
kernel image: https://storage.googleapis.com/syzbot-assets/18f8dc74ef68/bzImage-3f5b4c10.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e8625e...@syzkaller.appspotmail.com
loop4: detected capacity change from 0 to 32768
ocfs2: Mounting device (7,4) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.6.95-syzkaller #0 Not tainted
------------------------------------------------------
syz.4.5702/20708 is trying to acquire lock:
ffff88805606c2d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
ffff88805606c2d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:640 [inline]
ffff88805606c2d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x1a65/0x3360 fs/ocfs2/move_extents.c:860
but task is already holding lock:
ffff888056186d98 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
ffff888056186d98 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:632 [inline]
ffff888056186d98 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x1371/0x3360 fs/ocfs2/move_extents.c:860
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]#3){+.+.}-{3:3}:
down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
inode_lock include/linux/fs.h:804 [inline]
__ocfs2_flush_truncate_log+0x351/0x10b0 fs/ocfs2/alloc.c:6047
ocfs2_flush_truncate_log+0x4f/0x60 fs/ocfs2/alloc.c:6077
ocfs2_sync_fs+0x117/0x310 fs/ocfs2/super.c:402
sync_filesystem+0x1c2/0x220 fs/sync.c:66
generic_shutdown_super+0x6f/0x2b0 fs/super.c:666
kill_block_super+0x44/0x90 fs/super.c:1660
deactivate_locked_super+0x97/0x100 fs/super.c:481
cleanup_mnt+0x429/0x4c0 fs/namespace.c:1250
task_work_run+0x1ce/0x250 kernel/task_work.c:239
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+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
-> #0 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{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
inode_lock include/linux/fs.h:804 [inline]
ocfs2_move_extent fs/ocfs2/move_extents.c:640 [inline]
__ocfs2_move_extents_range+0x1a65/0x3360 fs/ocfs2/move_extents.c:860
ocfs2_move_extents+0x379/0x940 fs/ocfs2/move_extents.c:927
ocfs2_ioctl_move_extents+0x4e1/0x6c0 fs/ocfs2/move_extents.c:1053
ocfs2_ioctl+0x195/0x750 fs/ocfs2/ioctl.c:945
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
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:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2);
*** DEADLOCK ***
5 locks held by syz.4.5702/20708:
#0: ffff88805d1c4418 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x200 fs/namespace.c:447
#1: ffff88805606d118 (&sb->s_type->i_mutex_key#24){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#1: ffff88805606d118 (&sb->s_type->i_mutex_key#24){+.+.}-{3:3}, at: ocfs2_move_extents+0x1a3/0x940 fs/ocfs2/move_extents.c:905
#2: ffff88805606cda0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_move_extents+0x36c/0x940 fs/ocfs2/move_extents.c:925
#3: ffff8880561842d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#3: ffff8880561842d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x165/0x4360 fs/ocfs2/suballoc.c:782
#4: ffff888056186d98 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#4: ffff888056186d98 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:632 [inline]
#4: ffff888056186d98 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x1371/0x3360 fs/ocfs2/move_extents.c:860
stack backtrace:
CPU: 1 PID: 20708 Comm: syz.4.5702 Not tainted 6.6.95-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
inode_lock include/linux/fs.h:804 [inline]
ocfs2_move_extent fs/ocfs2/move_extents.c:640 [inline]
__ocfs2_move_extents_range+0x1a65/0x3360 fs/ocfs2/move_extents.c:860
ocfs2_move_extents+0x379/0x940 fs/ocfs2/move_extents.c:927
ocfs2_ioctl_move_extents+0x4e1/0x6c0 fs/ocfs2/move_extents.c:1053
ocfs2_ioctl+0x195/0x750 fs/ocfs2/ioctl.c:945
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
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: 0033:0x7f062578e929
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:00007f06266d5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f06259b5fa0 RCX: 00007f062578e929
RDX: 00002000000000c0 RSI: 0000000040406f06 RDI: 0000000000000004
RBP: 00007f0625810b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f06259b5fa0 R15: 00007ffe72ed9278
</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: 3f5b4c104b7d Linux 6.6.95
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=123c108c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b80883c3ded77c16
dashboard link: https://syzkaller.appspot.com/bug?extid=e8625e4e646b849e721a
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0efd4e01816e/disk-3f5b4c10.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f7c9d20858cc/vmlinux-3f5b4c10.xz
kernel image: https://storage.googleapis.com/syzbot-assets/18f8dc74ef68/bzImage-3f5b4c10.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e8625e...@syzkaller.appspotmail.com
loop4: detected capacity change from 0 to 32768
ocfs2: Mounting device (7,4) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.6.95-syzkaller #0 Not tainted
------------------------------------------------------
syz.4.5702/20708 is trying to acquire lock:
ffff88805606c2d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
ffff88805606c2d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:640 [inline]
ffff88805606c2d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x1a65/0x3360 fs/ocfs2/move_extents.c:860
but task is already holding lock:
ffff888056186d98 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
ffff888056186d98 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:632 [inline]
ffff888056186d98 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x1371/0x3360 fs/ocfs2/move_extents.c:860
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]#3){+.+.}-{3:3}:
down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
inode_lock include/linux/fs.h:804 [inline]
__ocfs2_flush_truncate_log+0x351/0x10b0 fs/ocfs2/alloc.c:6047
ocfs2_flush_truncate_log+0x4f/0x60 fs/ocfs2/alloc.c:6077
ocfs2_sync_fs+0x117/0x310 fs/ocfs2/super.c:402
sync_filesystem+0x1c2/0x220 fs/sync.c:66
generic_shutdown_super+0x6f/0x2b0 fs/super.c:666
kill_block_super+0x44/0x90 fs/super.c:1660
deactivate_locked_super+0x97/0x100 fs/super.c:481
cleanup_mnt+0x429/0x4c0 fs/namespace.c:1250
task_work_run+0x1ce/0x250 kernel/task_work.c:239
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+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
-> #0 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2){+.+.}-{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
inode_lock include/linux/fs.h:804 [inline]
ocfs2_move_extent fs/ocfs2/move_extents.c:640 [inline]
__ocfs2_move_extents_range+0x1a65/0x3360 fs/ocfs2/move_extents.c:860
ocfs2_move_extents+0x379/0x940 fs/ocfs2/move_extents.c:927
ocfs2_ioctl_move_extents+0x4e1/0x6c0 fs/ocfs2/move_extents.c:1053
ocfs2_ioctl+0x195/0x750 fs/ocfs2/ioctl.c:945
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
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:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3);
lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#2);
*** DEADLOCK ***
5 locks held by syz.4.5702/20708:
#0: ffff88805d1c4418 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x200 fs/namespace.c:447
#1: ffff88805606d118 (&sb->s_type->i_mutex_key#24){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#1: ffff88805606d118 (&sb->s_type->i_mutex_key#24){+.+.}-{3:3}, at: ocfs2_move_extents+0x1a3/0x940 fs/ocfs2/move_extents.c:905
#2: ffff88805606cda0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_move_extents+0x36c/0x940 fs/ocfs2/move_extents.c:925
#3: ffff8880561842d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#3: ffff8880561842d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x165/0x4360 fs/ocfs2/suballoc.c:782
#4: ffff888056186d98 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#4: ffff888056186d98 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:632 [inline]
#4: ffff888056186d98 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x1371/0x3360 fs/ocfs2/move_extents.c:860
stack backtrace:
CPU: 1 PID: 20708 Comm: syz.4.5702 Not tainted 6.6.95-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
inode_lock include/linux/fs.h:804 [inline]
ocfs2_move_extent fs/ocfs2/move_extents.c:640 [inline]
__ocfs2_move_extents_range+0x1a65/0x3360 fs/ocfs2/move_extents.c:860
ocfs2_move_extents+0x379/0x940 fs/ocfs2/move_extents.c:927
ocfs2_ioctl_move_extents+0x4e1/0x6c0 fs/ocfs2/move_extents.c:1053
ocfs2_ioctl+0x195/0x750 fs/ocfs2/ioctl.c:945
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
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: 0033:0x7f062578e929
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:00007f06266d5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f06259b5fa0 RCX: 00007f062578e929
RDX: 00002000000000c0 RSI: 0000000040406f06 RDI: 0000000000000004
RBP: 00007f0625810b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f06259b5fa0 R15: 00007ffe72ed9278
</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