REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
======================================================
WARNING: possible circular locking dependency detected
6.6.0-rc5-syzkaller-00055-g1c8b86a3799f #0 Not tainted
------------------------------------------------------
syz-executor200/5031 is trying to acquire lock:
ffff88814af56090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x7a/0xd0 fs/reiserfs/lock.c:27

but task is already holding lock:
ffff8880793702e0 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:837 [inline]
ffff8880793702e0 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: do_unlinkat+0x26a/0x950 fs/namei.c:4383

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}:
       down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1689
       inode_lock_nested include/linux/fs.h:837 [inline]
       do_unlinkat+0x26a/0x950 fs/namei.c:4383
       __do_sys_unlinkat fs/namei.c:4441 [inline]
       __se_sys_unlinkat fs/namei.c:4434 [inline]
       __x64_sys_unlinkat+0xce/0xf0 fs/namei.c:4434
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #1 (sb_writers#9){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1571 [inline]
       sb_start_write+0x4d/0x1c0 include/linux/fs.h:1646
       mnt_want_write_file+0x61/0x200 fs/namespace.c:447
       reiserfs_ioctl+0x178/0x2f0 fs/reiserfs/ioctl.c:103
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:871 [inline]
       __se_sys_ioctl+0xf8/0x170 fs/ioctl.c:857
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&sbi->lock){+.+.}-{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:3868 [inline]
       __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136
       lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747
       reiserfs_write_lock+0x7a/0xd0 fs/reiserfs/lock.c:27
       reiserfs_lookup+0x162/0x580 fs/reiserfs/namei.c:364
       lookup_one_qstr_excl+0x11b/0x250 fs/namei.c:1608
       do_unlinkat+0x298/0x950 fs/namei.c:4384
       __do_sys_unlinkat fs/namei.c:4441 [inline]
       __se_sys_unlinkat fs/namei.c:4434 [inline]
       __x64_sys_unlinkat+0xce/0xf0 fs/namei.c:4434
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
  &sbi->lock --> sb_writers#9 --> &type->i_mutex_dir_key#6/1

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&type->i_mutex_dir_key#6/1);
                               lock(sb_writers#9);
                               lock(&type->i_mutex_dir_key#6/1);
  lock(&sbi->lock);

 *** DEADLOCK ***

2 locks held by syz-executor200/5031:
 #0: ffff88801fb36410 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:403
 #1: ffff8880793702e0 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:837 [inline]
 #1: ffff8880793702e0 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: do_unlinkat+0x26a/0x950 fs/namei.c:4383

stack backtrace:
CPU: 0 PID: 5031 Comm: syz-executor200 Not tainted 6.6.0-rc5-syzkaller-00055-g1c8b86a3799f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x375/0x4a0 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:3868 [inline]
 __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136
 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747
 reiserfs_write_lock+0x7a/0xd0 fs/reiserfs/lock.c:27
 reiserfs_lookup+0x162/0x580 fs/reiserfs/namei.c:364
 lookup_one_qstr_excl+0x11b/0x250 fs/namei.c:1608
 do_unlinkat+0x298/0x950 fs/namei.c:4384
 __do_sys_unlinkat fs/namei.c:4441 [inline]
 __se_sys_unlinkat fs/namei.c:4434 [inline]
 __x64_sys_unlinkat+0xce/0xf0 fs/namei.c:4434
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f1cdaa6a779
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 90 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:00007fff7b55afd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007fff7b55b1a8 RCX: 00007f1cdaa6a779
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000005
RBP: 00007f1cdaade610 R08: 00007fff7b55b1a8 R09: 00007fff7b55b1a8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff7b55b198 R14: 0000000000000001 R15: 0000000000000001