======================================================
WARNING: possible circular locking dependency detected
6.15.0-rc6-syzkaller-00052-g9f35e33144ae #0 Not tainted
------------------------------------------------------
syz.4.943/9420 is trying to acquire lock:
ffff88801387b940 (&sbi->pipe_mutex){+.+.}-{4:4}, at: autofs_write fs/autofs/waitq.c:55 [inline]
ffff88801387b940 (&sbi->pipe_mutex){+.+.}-{4:4}, at: autofs_notify_daemon+0x4a6/0xd60 fs/autofs/waitq.c:164

but task is already holding lock:
ffff88804ff7d088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&of->mutex){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:601 [inline]
       __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746
       kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
       seq_read_iter+0x2c1/0x12c0 fs/seq_file.c:225
       kernfs_fop_read_iter+0x40f/0x5a0 fs/kernfs/file.c:279
       copy_splice_read+0x615/0xba0 fs/splice.c:363
       do_splice_read fs/splice.c:979 [inline]
       do_splice_read+0x285/0x370 fs/splice.c:953
       splice_direct_to_actor+0x2a1/0xa30 fs/splice.c:1083
       do_splice_direct_actor fs/splice.c:1201 [inline]
       do_splice_direct+0x174/0x240 fs/splice.c:1227
       do_sendfile+0xafd/0xe50 fs/read_write.c:1368
       __do_compat_sys_sendfile fs/read_write.c:1450 [inline]
       __se_compat_sys_sendfile fs/read_write.c:1433 [inline]
       __ia32_compat_sys_sendfile+0x1e5/0x220 fs/read_write.c:1433
       do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
       __do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #2 (&p->lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:601 [inline]
       __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746
       seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
       kernfs_fop_read_iter+0x40f/0x5a0 fs/kernfs/file.c:279
       copy_splice_read+0x615/0xba0 fs/splice.c:363
       do_splice_read fs/splice.c:979 [inline]
       do_splice_read+0x285/0x370 fs/splice.c:953
       splice_file_to_pipe+0x109/0x120 fs/splice.c:1289
       do_sendfile+0x400/0xe50 fs/read_write.c:1374
       __do_sys_sendfile64 fs/read_write.c:1429 [inline]
       __se_sys_sendfile64 fs/read_write.c:1415 [inline]
       __ia32_sys_sendfile64+0x1d7/0x220 fs/read_write.c:1415
       do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
       __do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #1 (&pipe->mutex){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:601 [inline]
       __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746
       anon_pipe_write+0x15d/0x1a70 fs/pipe.c:459
       __kernel_write_iter+0x71d/0xa90 fs/read_write.c:617
       __kernel_write+0xf5/0x140 fs/read_write.c:637
       autofs_write fs/autofs/waitq.c:57 [inline]
       autofs_notify_daemon+0x4db/0xd60 fs/autofs/waitq.c:164
       autofs_wait+0x10ca/0x1a70 fs/autofs/waitq.c:426
       autofs_mount_wait+0x132/0x380 fs/autofs/root.c:255
       autofs_d_automount+0x390/0x7f0 fs/autofs/root.c:401
       follow_automount fs/namei.c:1455 [inline]
       __traverse_mounts+0x192/0x790 fs/namei.c:1500
       traverse_mounts fs/namei.c:1529 [inline]
       handle_mounts fs/namei.c:1632 [inline]
       step_into+0x5aa/0x2270 fs/namei.c:1976
       open_last_lookups fs/namei.c:3827 [inline]
       path_openat+0x749/0x2d40 fs/namei.c:4036
       do_filp_open+0x20b/0x470 fs/namei.c:4066
       do_sys_openat2+0x11b/0x1d0 fs/open.c:1429
       do_sys_open fs/open.c:1444 [inline]
       __do_compat_sys_openat fs/open.c:1506 [inline]
       __se_compat_sys_openat fs/open.c:1504 [inline]
       __ia32_compat_sys_openat+0x16d/0x210 fs/open.c:1504
       do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
       __do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #0 (&sbi->pipe_mutex){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3166 [inline]
       check_prevs_add kernel/locking/lockdep.c:3285 [inline]
       validate_chain kernel/locking/lockdep.c:3909 [inline]
       __lock_acquire+0x1173/0x1ba0 kernel/locking/lockdep.c:5235
       lock_acquire kernel/locking/lockdep.c:5866 [inline]
       lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823
       __mutex_lock_common kernel/locking/mutex.c:601 [inline]
       __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746
       autofs_write fs/autofs/waitq.c:55 [inline]
       autofs_notify_daemon+0x4a6/0xd60 fs/autofs/waitq.c:164
       autofs_wait+0x10ca/0x1a70 fs/autofs/waitq.c:426
       autofs_mount_wait+0x132/0x380 fs/autofs/root.c:255
       autofs_d_automount+0x390/0x7f0 fs/autofs/root.c:401
       follow_automount fs/namei.c:1455 [inline]
       __traverse_mounts+0x192/0x790 fs/namei.c:1500
       traverse_mounts fs/namei.c:1529 [inline]
       handle_mounts fs/namei.c:1632 [inline]
       step_into+0x5aa/0x2270 fs/namei.c:1976
       walk_component+0xfc/0x5b0 fs/namei.c:2144
       lookup_last fs/namei.c:2636 [inline]
       path_lookupat+0x17e/0x780 fs/namei.c:2660
       filename_lookup+0x224/0x5f0 fs/namei.c:2689
       kern_path+0x35/0x50 fs/namei.c:2822
       lookup_bdev+0xd8/0x280 block/bdev.c:1205
       resume_store+0x1d6/0x460 kernel/power/hibernate.c:1248
       kobj_attr_store+0x55/0x80 lib/kobject.c:840
       sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
       kernfs_fop_write_iter+0x351/0x510 fs/kernfs/file.c:334
       new_sync_write fs/read_write.c:591 [inline]
       vfs_write+0x5bd/0x1180 fs/read_write.c:684
       ksys_write+0x12a/0x240 fs/read_write.c:736
       do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
       __do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

other info that might help us debug this:

Chain exists of:
  &sbi->pipe_mutex --> &p->lock --> &of->mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&of->mutex);
                               lock(&p->lock);
                               lock(&of->mutex);
  lock(&sbi->pipe_mutex);

 *** DEADLOCK ***

4 locks held by syz.4.943/9420:
 #0: ffff8880241a0d38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1213
 #1: ffff8880264b0420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x240 fs/read_write.c:736
 #2: ffff88804ff7d088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325
 #3: ffff8880412d9e18 (kn->active#73){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326

stack backtrace:
CPU: 1 UID: 0 PID: 9420 Comm: syz.4.943 Not tainted 6.15.0-rc6-syzkaller-00052-g9f35e33144ae #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2079
 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2211
 check_prev_add kernel/locking/lockdep.c:3166 [inline]
 check_prevs_add kernel/locking/lockdep.c:3285 [inline]
 validate_chain kernel/locking/lockdep.c:3909 [inline]
 __lock_acquire+0x1173/0x1ba0 kernel/locking/lockdep.c:5235
 lock_acquire kernel/locking/lockdep.c:5866 [inline]
 lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823
 __mutex_lock_common kernel/locking/mutex.c:601 [inline]
 __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746
 autofs_write fs/autofs/waitq.c:55 [inline]
 autofs_notify_daemon+0x4a6/0xd60 fs/autofs/waitq.c:164
 autofs_wait+0x10ca/0x1a70 fs/autofs/waitq.c:426
 autofs_mount_wait+0x132/0x380 fs/autofs/root.c:255
 autofs_d_automount+0x390/0x7f0 fs/autofs/root.c:401
 follow_automount fs/namei.c:1455 [inline]
 __traverse_mounts+0x192/0x790 fs/namei.c:1500
 traverse_mounts fs/namei.c:1529 [inline]
 handle_mounts fs/namei.c:1632 [inline]
 step_into+0x5aa/0x2270 fs/namei.c:1976
 walk_component+0xfc/0x5b0 fs/namei.c:2144
 lookup_last fs/namei.c:2636 [inline]
 path_lookupat+0x17e/0x780 fs/namei.c:2660
 filename_lookup+0x224/0x5f0 fs/namei.c:2689
 kern_path+0x35/0x50 fs/namei.c:2822
 lookup_bdev+0xd8/0x280 block/bdev.c:1205
 resume_store+0x1d6/0x460 kernel/power/hibernate.c:1248
 kobj_attr_store+0x55/0x80 lib/kobject.c:840
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x351/0x510 fs/kernfs/file.c:334
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x5bd/0x1180 fs/read_write.c:684
 ksys_write+0x12a/0x240 fs/read_write.c:736
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf708e579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f507e55c EFLAGS: 00000296 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000080000000
RDX: 0000000000000012 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 UID: 0 PID: 9420 Comm: syz.4.943 Not tainted 6.15.0-rc6-syzkaller-00052-g9f35e33144ae #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120
 fail_dump lib/fault-inject.c:73 [inline]
 should_fail_ex+0x512/0x640 lib/fault-inject.c:174
 should_failslab+0xc2/0x120 mm/failslab.c:46
 slab_pre_alloc_hook mm/slub.c:4100 [inline]
 slab_alloc_node mm/slub.c:4176 [inline]
 __kmalloc_cache_noprof+0x6a/0x3e0 mm/slub.c:4353
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 percpu_ref_init+0xec/0x410 lib/percpu-refcount.c:76
 mddev_init+0x6a/0x740 drivers/md/md.c:660
 mddev_alloc drivers/md/md.c:749 [inline]
 md_alloc+0xc7/0x1080 drivers/md/md.c:5865
 md_alloc_and_put drivers/md/md.c:5951 [inline]
 md_probe drivers/md/md.c:5964 [inline]
 md_probe+0x6e/0xd0 drivers/md/md.c:5959
 blk_probe_dev+0x116/0x1a0 block/genhd.c:823
 blk_request_module+0x16/0xb0 block/genhd.c:836
 blkdev_get_no_open+0x9b/0x100 block/bdev.c:825
 bdev_file_open_by_dev block/bdev.c:1046 [inline]
 bdev_file_open_by_dev+0x70/0x210 block/bdev.c:1034
 swsusp_check+0x74/0x420 kernel/power/swap.c:1589
 software_resume+0x6f/0x470 kernel/power/hibernate.c:999
 resume_store+0x247/0x460 kernel/power/hibernate.c:1277
 kobj_attr_store+0x55/0x80 lib/kobject.c:840
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x351/0x510 fs/kernfs/file.c:334
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x5bd/0x1180 fs/read_write.c:684
 ksys_write+0x12a/0x240 fs/read_write.c:736
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf708e579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f507e55c EFLAGS: 00000296 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000080000000
RDX: 0000000000000012 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
PM: Image not found (code -6)
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	10 06                	adc    %al,(%rsi)
   2:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   6:	10 07                	adc    %al,(%rdi)
   8:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   c:	10 08                	adc    %cl,(%rax)
   e:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1e:	00 51 52             	add    %dl,0x52(%rcx)
  21:	55                   	push   %rbp
  22:	89 e5                	mov    %esp,%ebp
  24:	0f 34                	sysenter
  26:	cd 80                	int    $0x80
* 28:	5d                   	pop    %rbp <-- trapping instruction
  29:	5a                   	pop    %rdx
  2a:	59                   	pop    %rcx
  2b:	c3                   	ret
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	90                   	nop
  2f:	90                   	nop
  30:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi
  37:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi