======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc1-syzkaller-00366-geb3479bc23fa #0 Not tainted
------------------------------------------------------
syz-executor.2/19912 is trying to acquire lock:
ffff888027c93b08 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb2/0xd10 fs/seq_file.c:182

but task is already holding lock:
ffff88807c156418 (sb_writers#4){.+.+}-{0:0}, at: do_sendfile+0x607/0x1000 fs/read_write.c:1253

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (sb_writers#4){.+.+}-{0:0}:
       lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5753
       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+0x3f/0x90 fs/namespace.c:404
       ovl_create_object+0x13b/0x360 fs/overlayfs/dir.c:629
       lookup_open fs/namei.c:3477 [inline]
       open_last_lookups fs/namei.c:3546 [inline]
       path_openat+0x13fa/0x3290 fs/namei.c:3776
       do_filp_open+0x234/0x490 fs/namei.c:3809
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1440
       do_sys_open fs/open.c:1455 [inline]
       __do_sys_openat fs/open.c:1471 [inline]
       __se_sys_openat fs/open.c:1466 [inline]
       __x64_sys_openat+0x247/0x290 fs/open.c:1466
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

-> #2 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}:
       lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5753
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526
       inode_lock_shared include/linux/fs.h:812 [inline]
       lookup_slow+0x45/0x70 fs/namei.c:1710
       walk_component+0x2d0/0x400 fs/namei.c:2002
       lookup_last fs/namei.c:2459 [inline]
       path_lookupat+0x16f/0x450 fs/namei.c:2483
       filename_lookup+0x255/0x610 fs/namei.c:2512
       kern_path+0x35/0x50 fs/namei.c:2610
       lookup_bdev+0xc5/0x290 block/bdev.c:977
       resume_store+0x1a0/0x710 kernel/power/hibernate.c:1177
       kernfs_fop_write_iter+0x3b3/0x510 fs/kernfs/file.c:334
       call_write_iter include/linux/fs.h:2020 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x792/0xb20 fs/read_write.c:584
       ksys_write+0x1a0/0x2c0 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

-> #1 (&of->mutex){+.+.}-{3:3}:
       lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5753
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747
       kernfs_seq_start+0x53/0x3a0 fs/kernfs/file.c:154
       seq_read_iter+0x3d4/0xd10 fs/seq_file.c:225
       call_read_iter include/linux/fs.h:2014 [inline]
       new_sync_read fs/read_write.c:389 [inline]
       vfs_read+0x78b/0xb00 fs/read_write.c:470
       ksys_read+0x1a0/0x2c0 fs/read_write.c:613
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

-> #0 (&p->lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18e4/0x59f0 kernel/locking/lockdep.c:3868
       __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5136
       lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5753
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747
       seq_read_iter+0xb2/0xd10 fs/seq_file.c:182
       call_read_iter include/linux/fs.h:2014 [inline]
       copy_splice_read+0x4c9/0x9c0 fs/splice.c:364
       splice_direct_to_actor+0x2c4/0x9e0 fs/splice.c:1069
       do_splice_direct+0x2ac/0x3f0 fs/splice.c:1194
       do_sendfile+0x62c/0x1000 fs/read_write.c:1254
       __do_sys_sendfile64 fs/read_write.c:1322 [inline]
       __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1308
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

other info that might help us debug this:

Chain exists of:
  &p->lock --> &ovl_i_mutex_dir_key[depth] --> sb_writers#4

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(sb_writers#4);
                               lock(&ovl_i_mutex_dir_key[depth]);
                               lock(sb_writers#4);
  lock(&p->lock);

 *** DEADLOCK ***

1 lock held by syz-executor.2/19912:
 #0: ffff88807c156418 (sb_writers#4){.+.+}-{0:0}, at: do_sendfile+0x607/0x1000 fs/read_write.c:1253

stack backtrace:
CPU: 1 PID: 19912 Comm: syz-executor.2 Not tainted 6.7.0-rc1-syzkaller-00366-geb3479bc23fa #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
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+0x18e4/0x59f0 kernel/locking/lockdep.c:3868
 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5136
 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5753
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747
 seq_read_iter+0xb2/0xd10 fs/seq_file.c:182
 call_read_iter include/linux/fs.h:2014 [inline]
 copy_splice_read+0x4c9/0x9c0 fs/splice.c:364
 splice_direct_to_actor+0x2c4/0x9e0 fs/splice.c:1069
 do_splice_direct+0x2ac/0x3f0 fs/splice.c:1194
 do_sendfile+0x62c/0x1000 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f9a9a07cae9
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:00007f9a9ad950c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f9a9a19bf80 RCX: 00007f9a9a07cae9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005
RBP: 00007f9a9a0c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000100800b5c R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f9a9a19bf80 R15: 00007fff9bfc4128
 </TASK>