======================================================
WARNING: possible circular locking dependency detected
6.7.0-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.5/11314 is trying to acquire lock:
ffff888038af0418 (sb_writers#21){.+.+}-{0:0}, at: mnt_want_write_file+0x61/0x200 fs/namespace.c:448

but task is already holding lock:
ffff888021273090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x7a/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}:
       lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
       __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_dirty_inode+0xf2/0x240 fs/reiserfs/super.c:704
       __mark_inode_dirty+0x305/0xda0 fs/fs-writeback.c:2452
       generic_update_time fs/inode.c:1943 [inline]
       inode_update_time fs/inode.c:1956 [inline]
       touch_atime+0x41e/0x660 fs/inode.c:2028
       file_accessed include/linux/fs.h:2360 [inline]
       generic_file_mmap+0xc6/0x120 mm/filemap.c:3620
       call_mmap include/linux/fs.h:2025 [inline]
       mmap_region+0xf47/0x1fa0 mm/mmap.c:2854
       do_mmap+0x76b/0xde0 mm/mmap.c:1379
       vm_mmap_pgoff+0x1e2/0x420 mm/util.c:556
       ksys_mmap_pgoff+0x4ff/0x6d0 mm/mmap.c:1425
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0x45/0x110 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

-> #0 (sb_writers#21){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x1909/0x5ab0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1635 [inline]
       sb_start_write+0x4d/0x1c0 include/linux/fs.h:1710
       mnt_want_write_file+0x61/0x200 fs/namespace.c:448
       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:52 [inline]
       do_syscall_64+0x45/0x110 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->lock);
                               lock(sb_writers#21);
                               lock(&sbi->lock);
  rlock(sb_writers#21);

 *** DEADLOCK ***

1 lock held by syz-executor.5/11314:
 #0: ffff888021273090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x7a/0xd0 fs/reiserfs/lock.c:27

stack backtrace:
CPU: 1 PID: 11314 Comm: syz-executor.5 Not tainted 6.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x366/0x490 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+0x1909/0x5ab0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1635 [inline]
 sb_start_write+0x4d/0x1c0 include/linux/fs.h:1710
 mnt_want_write_file+0x61/0x200 fs/namespace.c:448
 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:52 [inline]
 do_syscall_64+0x45/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7fd542a7cd29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd5438020c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd542bac1f0 RCX: 00007fd542a7cd29
RDX: 0000000020000180 RSI: 0000000040087602 RDI: 0000000000000008
RBP: 00007fd542ac947a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fd542bac1f0 R15: 00007fff66f70a88
 </TASK>