syzbot


possible deadlock in __ocfs2_move_extents_range

Status: upstream: reported on 2025/03/11 15:42
Reported-by: syzbot+3ed15bdbe4f8bfda409a@syzkaller.appspotmail.com
First crash: 433d, last: 25d
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in __ocfs2_move_extents_range ocfs2 4 318 280d 431d 0/29 auto-obsoleted due to no activity on 2025/10/20 12:22
linux-6.1 possible deadlock in __ocfs2_move_extents_range 4 126 4d18h 430d 0/3 upstream: reported on 2025/03/15 00:05
linux-6.6 possible deadlock in __ocfs2_move_extents_range 4 113 18d 325d 0/2 upstream: reported on 2025/06/27 23:37

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.2.28/4442 is trying to acquire lock:
ffff8880717342c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
ffff8880717342c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:646 [inline]
ffff8880717342c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x1a5f/0x35d0 fs/ocfs2/move_extents.c:866

but task is already holding lock:
ffff888071645f48 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
ffff888071645f48 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:638 [inline]
ffff888071645f48 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x137d/0x35d0 fs/ocfs2/move_extents.c:866

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]#6){+.+.}-{3:3}:
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       inode_lock include/linux/fs.h:787 [inline]
       __ocfs2_flush_truncate_log+0x357/0x1110 fs/ocfs2/alloc.c:6044
       ocfs2_flush_truncate_log fs/ocfs2/alloc.c:6074 [inline]
       ocfs2_try_to_free_truncate_log+0x1a5/0x350 fs/ocfs2/alloc.c:6133
       ocfs2_write_begin_nolock+0x338b/0x4400 fs/ocfs2/aops.c:1871
       ocfs2_dio_wr_get_block+0xbb6/0x1820 fs/ocfs2/aops.c:2239
       get_more_blocks fs/direct-io.c:673 [inline]
       do_direct_IO fs/direct-io.c:959 [inline]
       do_blockdev_direct_IO fs/direct-io.c:1276 [inline]
       __blockdev_direct_IO+0x13d4/0x3a70 fs/direct-io.c:1368
       ocfs2_direct_IO+0x233/0x2a0 fs/ocfs2/aops.c:2468
       generic_file_direct_write+0x22c/0x490 mm/filemap.c:3687
       __generic_file_write_iter+0x2b1/0x4e0 mm/filemap.c:3869
       ocfs2_file_write_iter+0x1670/0x1e70 fs/ocfs2/file.c:2472
       do_iter_readv_writev+0x47e/0x5f0 fs/read_write.c:-1
       do_iter_write+0x205/0x7b0 fs/read_write.c:855
       iter_file_splice_write+0x699/0xcc0 fs/splice.c:689
       do_splice_from fs/splice.c:767 [inline]
       direct_splice_actor+0xe1/0x130 fs/splice.c:956
       splice_direct_to_actor+0x4ea/0xc10 fs/splice.c:902
       do_splice_direct+0x1d4/0x2f0 fs/splice.c:1008
       do_sendfile+0x5fc/0xeb0 fs/read_write.c:1249
       __do_sys_sendfile64 fs/read_write.c:1317 [inline]
       __se_sys_sendfile64+0x141/0x1a0 fs/read_write.c:1303
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
       lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       inode_lock include/linux/fs.h:787 [inline]
       ocfs2_move_extent fs/ocfs2/move_extents.c:646 [inline]
       __ocfs2_move_extents_range+0x1a5f/0x35d0 fs/ocfs2/move_extents.c:866
       ocfs2_move_extents+0x3ad/0x9c0 fs/ocfs2/move_extents.c:938
       ocfs2_ioctl_move_extents+0x523/0x6c0 fs/ocfs2/move_extents.c:1064
       ocfs2_ioctl+0x31f/0x7a0 fs/ocfs2/ioctl.c:931
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:874 [inline]
       __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

5 locks held by syz.2.28/4442:
 #0: ffff8880288ca460 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:430
 #1: ffff888071735108 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff888071735108 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: ocfs2_move_extents+0x19e/0x9c0 fs/ocfs2/move_extents.c:916
 #2: ffff888071734da0 (&oi->ip_alloc_sem){++++}-{3:3}, at: ocfs2_move_extents+0x3a0/0x9c0 fs/ocfs2/move_extents.c:936
 #3: ffff8880717309c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #3: ffff8880717309c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x16a/0x44d0 fs/ocfs2/suballoc.c:782
 #4: ffff888071645f48 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #4: ffff888071645f48 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: ocfs2_move_extent fs/ocfs2/move_extents.c:638 [inline]
 #4: ffff888071645f48 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: __ocfs2_move_extents_range+0x137d/0x35d0 fs/ocfs2/move_extents.c:866

stack backtrace:
CPU: 0 PID: 4442 Comm: syz.2.28 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 down_write+0x38/0x60 kernel/locking/rwsem.c:1551
 inode_lock include/linux/fs.h:787 [inline]
 ocfs2_move_extent fs/ocfs2/move_extents.c:646 [inline]
 __ocfs2_move_extents_range+0x1a5f/0x35d0 fs/ocfs2/move_extents.c:866
 ocfs2_move_extents+0x3ad/0x9c0 fs/ocfs2/move_extents.c:938
 ocfs2_ioctl_move_extents+0x523/0x6c0 fs/ocfs2/move_extents.c:1064
 ocfs2_ioctl+0x31f/0x7a0 fs/ocfs2/ioctl.c:931
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f27cb9ccdd9
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:00007f27c9be4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f27cbc46180 RCX: 00007f27cb9ccdd9
RDX: 0000200000000080 RSI: 0000000040406f06 RDI: 0000000000000004
RBP: 00007f27cba62d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f27cbc46218 R14: 00007f27cbc46180 R15: 00007fffca527a68
 </TASK>

Crashes (24):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/24 07:47 linux-5.15.y b9d57c40a767 9cfb3ca7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in __ocfs2_move_extents_range
2026/04/17 14:18 linux-5.15.y 91d48252ad4b de0a551d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in __ocfs2_move_extents_range
2026/03/12 17:46 linux-5.15.y 91d48252ad4b 4efadf07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in __ocfs2_move_extents_range
2026/02/10 06:15 linux-5.15.y 7b232985052f 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in __ocfs2_move_extents_range
2025/12/07 16:58 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in __ocfs2_move_extents_range
2025/11/29 10:42 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in __ocfs2_move_extents_range
2025/10/29 06:17 linux-5.15.y ac56c046adf4 fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in __ocfs2_move_extents_range
2025/05/04 06:39 linux-5.15.y 16fdf2c7111b b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in __ocfs2_move_extents_range
2025/05/04 06:19 linux-5.15.y 16fdf2c7111b b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in __ocfs2_move_extents_range
2025/04/26 04:35 linux-5.15.y f7347f400572 c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in __ocfs2_move_extents_range
2025/03/11 15:42 linux-5.15.y c16c81c81336 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in __ocfs2_move_extents_range
2025/08/26 21:29 linux-5.15.y c79648372d02 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in __ocfs2_move_extents_range
2025/08/19 09:31 linux-5.15.y c79648372d02 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in __ocfs2_move_extents_range
2025/08/12 21:42 linux-5.15.y c79648372d02 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in __ocfs2_move_extents_range
2025/07/20 16:35 linux-5.15.y c79648372d02 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in __ocfs2_move_extents_range
2025/07/01 20:15 linux-5.15.y 3dea0e7f549e 091a06cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in __ocfs2_move_extents_range
2025/07/01 19:46 linux-5.15.y 3dea0e7f549e 091a06cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in __ocfs2_move_extents_range
2025/06/25 23:09 linux-5.15.y 1c700860e8bc 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in __ocfs2_move_extents_range
2025/06/22 05:24 linux-5.15.y 1c700860e8bc d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in __ocfs2_move_extents_range
2025/06/19 11:15 linux-5.15.y 1c700860e8bc ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in __ocfs2_move_extents_range
2025/06/14 05:47 linux-5.15.y 1c700860e8bc 0e8da31f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in __ocfs2_move_extents_range
2025/05/26 03:52 linux-5.15.y 98f47d0e9b8c 2d4582d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in __ocfs2_move_extents_range
2025/05/22 23:18 linux-5.15.y 98f47d0e9b8c 0919b50b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in __ocfs2_move_extents_range
2025/04/22 15:05 linux-5.15.y f7347f400572 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in __ocfs2_move_extents_range
* Struck through repros no longer work on HEAD.