REISERFS (device loop1): checking transaction log (loop1)
REISERFS (device loop1): Using r5 hash to sort names
REISERFS (device loop1): Created .reiserfs_priv - reserved for xattr storage.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.967/9371 is trying to acquire lock:
ffff88801ef7c418 (sb_writers#22){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x200 fs/namespace.c:456

but task is already holding lock:
ffff88802d0b3090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x79/0xd0 fs/reiserfs/lock.c:27

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sbi->lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747
       reiserfs_write_lock+0x79/0xd0 fs/reiserfs/lock.c:27
       reiserfs_dirty_inode+0x111/0x270 fs/reiserfs/super.c:704
       __mark_inode_dirty+0x2cc/0xc90 fs/fs-writeback.c:2471
       generic_update_time fs/inode.c:1981 [inline]
       inode_update_time fs/inode.c:1994 [inline]
       touch_atime+0x346/0x570 fs/inode.c:2065
       file_accessed include/linux/fs.h:2358 [inline]
       generic_file_mmap+0xc8/0x130 mm/filemap.c:3729
       call_mmap include/linux/fs.h:2023 [inline]
       mmap_file mm/internal.h:98 [inline]
       __mmap_region mm/mmap.c:2790 [inline]
       mmap_region+0xf8e/0x2000 mm/mmap.c:2941
       do_mmap+0x92c/0x10a0 mm/mmap.c:1385
       vm_mmap_pgoff+0x1c4/0x3f0 mm/util.c:556
       ksys_mmap_pgoff+0x520/0x700 mm/mmap.c:1431
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (sb_writers#22){.+.+}-{0:0}:
       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+0x2df1/0x7d40 kernel/locking/lockdep.c:5137
       lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1633 [inline]
       sb_start_write+0x4d/0x1c0 include/linux/fs.h:1708
       mnt_want_write_file+0x63/0x200 fs/namespace.c:456
       reiserfs_ioctl+0x112/0x2d0 fs/reiserfs/ioctl.c:103
       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:46 [inline]
       do_syscall_64+0x55/0xa0 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(&sbi->lock);
                               lock(sb_writers#22);
                               lock(&sbi->lock);
  rlock(sb_writers#22);

 *** DEADLOCK ***

1 lock held by syz.1.967/9371:
 #0: ffff88802d0b3090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x79/0xd0 fs/reiserfs/lock.c:27

stack backtrace:
CPU: 0 PID: 9371 Comm: syz.1.967 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_noncircular+0x2fc/0x400 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+0x2df1/0x7d40 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1633 [inline]
 sb_start_write+0x4d/0x1c0 include/linux/fs.h:1708
 mnt_want_write_file+0x63/0x200 fs/namespace.c:456
 reiserfs_ioctl+0x112/0x2d0 fs/reiserfs/ioctl.c:103
 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:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2d4d99cdd9
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:00007f2d4bbf6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2d4dc15fa0 RCX: 00007f2d4d99cdd9
RDX: 0000000000000000 RSI: 0000000040087602 RDI: 0000000000000004
RBP: 00007f2d4da32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2d4dc16038 R14: 00007f2d4dc15fa0 R15: 00007ffcbcd85b98
 </TASK>