REISERFS (device loop3): Created .reiserfs_priv - reserved for xattr storage.
======================================================
WARNING: possible circular locking dependency detected
6.1.98-syzkaller #0 Not tainted
------------------------------------------------------
syz.3.839/6620 is trying to acquire lock:
ffff888064f80460 (sb_writers#26){.+.+}-{0:0}, at: mnt_want_write_file+0x5a/0x1f0 fs/namespace.c:437

but task is already holding lock:
ffff888018fe8090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x76/0xd0 fs/reiserfs/lock.c:27

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&sbi->lock){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       reiserfs_write_lock+0x76/0xd0 fs/reiserfs/lock.c:27
       reiserfs_lookup+0x15c/0x4b0 fs/reiserfs/namei.c:364
       lookup_one_qstr_excl+0x117/0x240 fs/namei.c:1605
       filename_create+0x293/0x530 fs/namei.c:3879
       do_mkdirat+0xba/0x360 fs/namei.c:4123
       __do_sys_mkdirat fs/namei.c:4148 [inline]
       __se_sys_mkdirat fs/namei.c:4146 [inline]
       __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4146
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_write_nested+0x39/0x60 kernel/locking/rwsem.c:1689
       inode_lock_nested include/linux/fs.h:793 [inline]
       filename_create+0x25c/0x530 fs/namei.c:3878
       do_mkdirat+0xba/0x360 fs/namei.c:4123
       __do_sys_mkdirat fs/namei.c:4148 [inline]
       __se_sys_mkdirat fs/namei.c:4146 [inline]
       __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4146
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (sb_writers#26){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1891 [inline]
       sb_start_write+0x4d/0x1c0 include/linux/fs.h:1966
       mnt_want_write_file+0x5a/0x1f0 fs/namespace.c:437
       reiserfs_ioctl+0x170/0x340 fs/reiserfs/ioctl.c:103
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  sb_writers#26 --> &type->i_mutex_dir_key#20/1 --> &sbi->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->lock);
                               lock(&type->i_mutex_dir_key#20/1);
                               lock(&sbi->lock);
  lock(sb_writers#26);

 *** DEADLOCK ***

1 lock held by syz.3.839/6620:
 #0: ffff888018fe8090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x76/0xd0 fs/reiserfs/lock.c:27

stack backtrace:
CPU: 1 PID: 6620 Comm: syz.3.839 Not tainted 6.1.98-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1891 [inline]
 sb_start_write+0x4d/0x1c0 include/linux/fs.h:1966
 mnt_want_write_file+0x5a/0x1f0 fs/namespace.c:437
 reiserfs_ioctl+0x170/0x340 fs/reiserfs/ioctl.c:103
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fea38175bd9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fea38f17048 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fea38303f60 RCX: 00007fea38175bd9
RDX: 0000000000000000 RSI: 0000000040087602 RDI: 0000000000000004
RBP: 00007fea381e4e60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fea38303f60 R15: 00007fff7fdbad68
 </TASK>