syzbot


possible deadlock in ext4_bmap

Status: upstream: reported C repro on 2023/03/07 16:42
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+5bc75b63c58b40e14b5b@syzkaller.appspotmail.com
First crash: 552d, last: 1h52m
Bug presence (2)
Date Name Commit Repro Result
2023/05/03 linux-5.15.y (ToT) 8a7f2a5c5aa1 C [report] possible deadlock in ext4_bmap
2023/05/03 upstream (ToT) 348551ddaf31 C Didn't crash
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 possible deadlock in ext4_bmap origin:lts-only C done 22611 12d 552d 0/3 upstream: reported C repro on 2023/03/07 17:07
upstream possible deadlock in ext4_bmap ext4 C error 78083 459d 763d 22/27 fixed on 2023/06/08 14:41
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2023/10/06 13:30 1h55m fix candidate upstream OK (0) job log

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
5.15.156-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor854/3498 is trying to acquire lock:
ffff8880122803f0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:799 [inline]
ffff8880122803f0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_bmap+0x4b/0x410 fs/ext4/inode.c:3152

but task is already holding lock:
ffff88814b2723f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x31c/0xc90 fs/jbd2/journal.c:2478

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&journal->j_checkpoint_mutex){+.+.}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
       mutex_lock_io_nested+0x45/0x60 kernel/locking/mutex.c:777
       jbd2_journal_flush+0x290/0xc90 fs/jbd2/journal.c:2468
       ext4_ioctl_checkpoint fs/ext4/ioctl.c:849 [inline]
       __ext4_ioctl fs/ext4/ioctl.c:1267 [inline]
       ext4_ioctl+0x3249/0x5b80 fs/ext4/ioctl.c:1276
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:874 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #3 (&journal->j_barrier){+.+.}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       jbd2_journal_lock_updates+0x2aa/0x370 fs/jbd2/transaction.c:905
       ext4_change_inode_journal_flag+0x1a8/0x6e0 fs/ext4/inode.c:6041
       ext4_ioctl_setflags fs/ext4/ioctl.c:448 [inline]
       ext4_fileattr_set+0xdf4/0x1750 fs/ext4/ioctl.c:765
       vfs_fileattr_set+0x8f3/0xd30 fs/ioctl.c:700
       ioctl_setflags fs/ioctl.c:732 [inline]
       do_vfs_ioctl+0x1d85/0x2b70 fs/ioctl.c:843
       __do_sys_ioctl fs/ioctl.c:872 [inline]
       __se_sys_ioctl+0x81/0x160 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #2 (&sbi->s_writepages_rwsem){++++}-{0:0}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       percpu_down_write+0x52/0x2d0 kernel/locking/percpu-rwsem.c:217
       ext4_change_inode_journal_flag+0x1a0/0x6e0 fs/ext4/inode.c:6040
       ext4_ioctl_setflags fs/ext4/ioctl.c:448 [inline]
       ext4_fileattr_set+0xdf4/0x1750 fs/ext4/ioctl.c:765
       vfs_fileattr_set+0x8f3/0xd30 fs/ioctl.c:700
       ioctl_setflags fs/ioctl.c:732 [inline]
       do_vfs_ioctl+0x1d85/0x2b70 fs/ioctl.c:843
       __do_sys_ioctl fs/ioctl.c:872 [inline]
       __se_sys_ioctl+0x81/0x160 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #1 (mapping.invalidate_lock){++++}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       filemap_invalidate_lock include/linux/fs.h:834 [inline]
       ext4_setattr+0xd6c/0x1990 fs/ext4/inode.c:5459
       notify_change+0xc6d/0xf50 fs/attr.c:505
       do_truncate+0x21c/0x300 fs/open.c:65
       do_sys_ftruncate+0x2eb/0x390 fs/open.c:193
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       down_read+0x45/0x2e0 kernel/locking/rwsem.c:1498
       inode_lock_shared include/linux/fs.h:799 [inline]
       ext4_bmap+0x4b/0x410 fs/ext4/inode.c:3152
       bmap+0xa1/0xd0 fs/inode.c:1756
       jbd2_journal_bmap fs/jbd2/journal.c:980 [inline]
       __jbd2_journal_erase fs/jbd2/journal.c:1790 [inline]
       jbd2_journal_flush+0x7a2/0xc90 fs/jbd2/journal.c:2496
       ext4_ioctl_checkpoint fs/ext4/ioctl.c:849 [inline]
       __ext4_ioctl fs/ext4/ioctl.c:1267 [inline]
       ext4_ioctl+0x3249/0x5b80 fs/ext4/ioctl.c:1276
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:874 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

Chain exists of:
  &sb->s_type->i_mutex_key#9 --> &journal->j_barrier --> &journal->j_checkpoint_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&journal->j_checkpoint_mutex);
                               lock(&journal->j_barrier);
                               lock(&journal->j_checkpoint_mutex);
  lock(&sb->s_type->i_mutex_key#9);

 *** DEADLOCK ***

2 locks held by syz-executor854/3498:
 #0: ffff88814b272170 (&journal->j_barrier){+.+.}-{3:3}, at: jbd2_journal_lock_updates+0x2aa/0x370 fs/jbd2/transaction.c:905
 #1: ffff88814b2723f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x31c/0xc90 fs/jbd2/journal.c:2478

stack backtrace:
CPU: 1 PID: 3498 Comm: syz-executor854 Not tainted 5.15.156-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x2f8/0x3b0 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+0x1649/0x5930 kernel/locking/lockdep.c:3788
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 down_read+0x45/0x2e0 kernel/locking/rwsem.c:1498
 inode_lock_shared include/linux/fs.h:799 [inline]
 ext4_bmap+0x4b/0x410 fs/ext4/inode.c:3152
 bmap+0xa1/0xd0 fs/inode.c:1756
 jbd2_journal_bmap fs/jbd2/journal.c:980 [inline]
 __jbd2_journal_erase fs/jbd2/journal.c:1790 [inline]
 jbd2_journal_flush+0x7a2/0xc90 fs/jbd2/journal.c:2496
 ext4_ioctl_checkpoint fs/ext4/ioctl.c:849 [inline]
 __ext4_ioctl fs/ext4/ioctl.c:1267 [inline]
 ext4_ioctl+0x3249/0x5b80 fs/ext4/ioctl.c:1276
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2227d21369
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe6a728b88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0073746e6576652e RCX: 00007f2227d21369
RDX: 0000000020000000 RSI: 000000004004662b RDI: 0000000000000005
RBP: 652e79726f6d656d R08: 00000000000ac5f8 R09: 00000000000ac5f8
R10: 00000000000ac5f8 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe6a728d58 R14: 0000000000000001 R15: 0000000000000001

Crashes (22232):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/19 18:20 linux-5.15.y c52b9710c83d af24b050 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2024/04/19 09:34 linux-5.15.y c52b9710c83d af24b050 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2024/01/10 06:54 linux-5.15.y 26c690eff0a5 b438bd66 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/29 10:29 linux-5.15.y 12952a23a5da 3c418d72 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/03/10 04:12 linux-5.15.y d9b4a0c83a2d f08b59ac .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/08/22 04:18 linux-5.15.y f6f7927ac664 6b415825 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/06/24 05:18 linux-5.15.y f67653019430 79782afc .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/06/18 05:54 linux-5.15.y 471e639e59d1 f3921d4d .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/03/08 01:37 linux-5.15.y d9b4a0c83a2d d7ea8bc4 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/09/09 17:48 linux-5.15.y 14e468424d3e 073f8be2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/09/05 18:49 linux-5.15.y 14e468424d3e 464ac2ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/09/05 07:51 linux-5.15.y 14e468424d3e dfbe2ed4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/09/02 20:02 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/09/01 12:52 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/31 20:48 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/28 17:37 linux-5.15.y fa93fa65db6e ef3de9e8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/28 06:42 linux-5.15.y fa93fa65db6e 6c853ff9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/26 18:46 linux-5.15.y fa93fa65db6e 9aee4e0b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/23 08:09 linux-5.15.y fa93fa65db6e ce8a9099 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/22 07:11 linux-5.15.y fa93fa65db6e ca02180f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/21 19:14 linux-5.15.y fa93fa65db6e db5852f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/21 14:34 linux-5.15.y fa93fa65db6e db5852f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/20 23:54 linux-5.15.y fa93fa65db6e 9f0ab3fb .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/20 18:12 linux-5.15.y fa93fa65db6e 9f0ab3fb .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/20 17:11 linux-5.15.y fa93fa65db6e 9f0ab3fb .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/18 15:49 linux-5.15.y 7e89efd3ae1c dbc93b08 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/18 07:44 linux-5.15.y 7e89efd3ae1c dbc93b08 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/16 07:15 linux-5.15.y 7e89efd3ae1c e4bacdaf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/13 07:32 linux-5.15.y 7e89efd3ae1c 7b0f4b46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/13 06:16 linux-5.15.y 7e89efd3ae1c 7b0f4b46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/12 03:58 linux-5.15.y 7e89efd3ae1c 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/09 13:18 linux-5.15.y 7e89efd3ae1c a83d9288 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/08 19:00 linux-5.15.y 7e89efd3ae1c 61405512 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/07 05:06 linux-5.15.y 7e89efd3ae1c 1ef9fe42 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/08/03 21:23 linux-5.15.y 7e89efd3ae1c 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2024/07/02 03:53 linux-5.15.y 4878aadf2d15 b294e901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2024/09/06 20:18 linux-5.15.y 14e468424d3e 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/09/05 06:44 linux-5.15.y 14e468424d3e dfbe2ed4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/09/03 18:59 linux-5.15.y fa93fa65db6e 326f9c5a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/09/02 10:49 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/09/02 08:55 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/08/31 04:20 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/08/30 21:57 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/08/29 21:43 linux-5.15.y fa93fa65db6e 9bd464fc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/08/29 01:21 linux-5.15.y fa93fa65db6e ef3de9e8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/08/28 03:45 linux-5.15.y fa93fa65db6e 6c853ff9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/08/26 08:53 linux-5.15.y fa93fa65db6e d7d32352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/08/23 15:47 linux-5.15.y fa93fa65db6e d7d32352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/08/23 03:21 linux-5.15.y fa93fa65db6e ce8a9099 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/08/21 03:33 linux-5.15.y fa93fa65db6e 9f0ab3fb .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/08/14 09:19 linux-5.15.y 7e89efd3ae1c 07a4d4ad .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/08/12 13:07 linux-5.15.y 7e89efd3ae1c 842184b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2024/08/06 12:39 linux-5.15.y 7e89efd3ae1c e1bdb00a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in ext4_bmap
2023/03/07 16:42 linux-5.15.y d9b4a0c83a2d d7ea8bc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
* Struck through repros no longer work on HEAD.