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: 210d, last: now
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 10936 11m 210d 0/3 upstream: reported C repro on 2023/03/07 17:07
upstream possible deadlock in ext4_bmap ext4 C error 78083 118d 422d 24/25 fixed on 2023/06/08 14:41

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
5.15.98-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor110/3584 is trying to acquire lock:
ffff88801fc483f0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
ffff88801fc483f0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_bmap+0x4b/0x410 fs/ext4/inode.c:3159

but task is already holding lock:
ffff88814bc363f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x31c/0xc90 fs/jbd2/journal.c:2474

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&journal->j_checkpoint_mutex){+.+.}-{3:3}:
       lock_acquire+0x1f6/0x560 kernel/locking/lockdep.c:5622
       __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:2464
       ext4_ioctl_checkpoint fs/ext4/ioctl.c:847 [inline]
       __ext4_ioctl fs/ext4/ioctl.c:1265 [inline]
       ext4_ioctl+0x335b/0x5db0 fs/ext4/ioctl.c:1277
       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+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #2 (&journal->j_barrier){+.+.}-{3:3}:
       lock_acquire+0x1f6/0x560 kernel/locking/lockdep.c:5622
       __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+0x4a9/0x580 fs/jbd2/transaction.c:895
       ext4_change_inode_journal_flag+0x1a8/0x6e0 fs/ext4/inode.c:6026
       ext4_ioctl_setflags fs/ext4/ioctl.c:447 [inline]
       ext4_fileattr_set+0xe6e/0x17d0 fs/ext4/ioctl.c:762
       vfs_fileattr_set+0x8ee/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+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #1 (&sbi->s_writepages_rwsem){++++}-{0:0}:
       lock_acquire+0x1f6/0x560 kernel/locking/lockdep.c:5622
       percpu_down_write+0x52/0x2d0 kernel/locking/percpu-rwsem.c:217
       ext4_ind_migrate+0x254/0x760 fs/ext4/migrate.c:625
       ext4_ioctl_setflags fs/ext4/ioctl.c:456 [inline]
       ext4_fileattr_set+0xf13/0x17d0 fs/ext4/ioctl.c:762
       vfs_fileattr_set+0x8ee/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+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #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+0x1646/0x58b0 kernel/locking/lockdep.c:3787
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
       lock_acquire+0x1f6/0x560 kernel/locking/lockdep.c:5622
       down_read+0x3b/0x50 kernel/locking/rwsem.c:1480
       inode_lock_shared include/linux/fs.h:797 [inline]
       ext4_bmap+0x4b/0x410 fs/ext4/inode.c:3159
       bmap+0xa1/0xd0 fs/inode.c:1714
       jbd2_journal_bmap fs/jbd2/journal.c:978 [inline]
       __jbd2_journal_erase fs/jbd2/journal.c:1786 [inline]
       jbd2_journal_flush+0x7a2/0xc90 fs/jbd2/journal.c:2492
       ext4_ioctl_checkpoint fs/ext4/ioctl.c:847 [inline]
       __ext4_ioctl fs/ext4/ioctl.c:1265 [inline]
       ext4_ioctl+0x335b/0x5db0 fs/ext4/ioctl.c:1277
       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+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

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-executor110/3584:
 #0: ffff88814bc36170 (&journal->j_barrier){+.+.}-{3:3}, at: jbd2_journal_lock_updates+0x4a9/0x580 fs/jbd2/transaction.c:895
 #1: ffff88814bc363f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x31c/0xc90 fs/jbd2/journal.c:2474

stack backtrace:
CPU: 1 PID: 3584 Comm: syz-executor110 Not tainted 5.15.98-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb 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+0x1646/0x58b0 kernel/locking/lockdep.c:3787
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
 lock_acquire+0x1f6/0x560 kernel/locking/lockdep.c:5622
 down_read+0x3b/0x50 kernel/locking/rwsem.c:1480
 inode_lock_shared include/linux/fs.h:797 [inline]
 ext4_bmap+0x4b/0x410 fs/ext4/inode.c:3159
 bmap+0xa1/0xd0 fs/inode.c:1714
 jbd2_journal_bmap fs/jbd2/journal.c:978 [inline]
 __jbd2_journal_erase fs/jbd2/journal.c:1786 [inline]
 jbd2_journal_flush+0x7a2/0xc90 fs/jbd2/journal.c:2492
 ext4_ioctl_checkpoint fs/ext4/ioctl.c:847 [inline]
 __ext4_ioctl fs/ext4/ioctl.c:1265 [inline]
 ext4_ioctl+0x335b/0x5db0 fs/ext4/ioctl.c:1277
 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+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fde8a715059
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdeeab1ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fde8a715059
RDX: 0000000020000700 RSI: 000000004004662b RDI: 0000000000000004
RBP: 00007fde8a6d9040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000

Crashes (10539):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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
2023/10/04 14:15 linux-5.15.y b911329317b4 b7d7ff54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/04 13:09 linux-5.15.y b911329317b4 b7d7ff54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/04 12:29 linux-5.15.y b911329317b4 b7d7ff54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/04 11:01 linux-5.15.y b911329317b4 b7d7ff54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/04 09:48 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/03 22:50 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/03 18:48 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/03 16:39 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/03 15:08 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/03 11:59 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/03 10:25 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/03 07:48 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/03 06:46 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/03 05:29 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/03 04:19 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/03 02:50 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/03 02:39 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/03 01:15 linux-5.15.y b911329317b4 65faba36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/03 00:05 linux-5.15.y b911329317b4 50b20e75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/02 21:57 linux-5.15.y b911329317b4 50b20e75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/02 20:54 linux-5.15.y b911329317b4 50b20e75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/02 20:21 linux-5.15.y b911329317b4 50b20e75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/02 19:11 linux-5.15.y b911329317b4 50b20e75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/02 18:06 linux-5.15.y b911329317b4 50b20e75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/02 16:30 linux-5.15.y b911329317b4 50b20e75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/02 15:21 linux-5.15.y b911329317b4 50b20e75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/02 14:05 linux-5.15.y b911329317b4 50b20e75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/02 12:58 linux-5.15.y b911329317b4 50b20e75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/02 11:53 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/02 10:46 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/02 09:23 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/02 04:37 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/02 04:25 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/01 19:33 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/01 18:25 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/01 16:54 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/01 14:47 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/01 12:57 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/01 05:56 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/10/01 01:54 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/10/01 00:41 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/09/30 21:03 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/09/30 15:34 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf possible deadlock in ext4_bmap
2023/09/30 12:19 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in ext4_bmap
2023/09/29 19:57 linux-5.15.y b911329317b4 8e26a358 .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.