====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc5-syzkaller-00158-g3013c33dcbd9 #0 Not tainted ------------------------------------------------------ syz.7.4441/24880 is trying to acquire lock: ffff8880606a1140 (&sbi->pipe_mutex){+.+.}-{4:4}, at: autofs_write fs/autofs/waitq.c:55 [inline] ffff8880606a1140 (&sbi->pipe_mutex){+.+.}-{4:4}, at: autofs_notify_daemon+0x735/0xe50 fs/autofs/waitq.c:164 but task is already holding lock: ffff888065042088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&of->mutex){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746 kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 iter_file_splice_write+0x93a/0x1000 fs/splice.c:738 do_splice_from fs/splice.c:935 [inline] do_splice+0xc79/0x1660 fs/splice.c:1348 __do_splice fs/splice.c:1430 [inline] __do_sys_splice fs/splice.c:1633 [inline] __se_sys_splice+0x2e1/0x460 fs/splice.c:1615 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&pipe->mutex){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746 anon_pipe_write+0x16a/0x1360 fs/pipe.c:459 __kernel_write_iter+0x3ec/0x860 fs/read_write.c:617 __kernel_write+0xef/0x150 fs/read_write.c:637 autofs_write fs/autofs/waitq.c:57 [inline] autofs_notify_daemon+0x748/0xe50 fs/autofs/waitq.c:164 autofs_wait+0x11dc/0x1870 fs/autofs/waitq.c:426 autofs_mount_wait+0x16b/0x330 fs/autofs/root.c:255 autofs_d_automount+0x393/0x720 fs/autofs/root.c:401 follow_automount fs/namei.c:1455 [inline] __traverse_mounts+0x308/0x5b0 fs/namei.c:1500 traverse_mounts fs/namei.c:1529 [inline] handle_mounts fs/namei.c:1632 [inline] step_into+0x534/0xf30 fs/namei.c:1976 open_last_lookups fs/namei.c:3827 [inline] path_openat+0x1bc6/0x3830 fs/namei.c:4036 do_filp_open+0x1fa/0x410 fs/namei.c:4066 do_sys_openat2+0x121/0x1c0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #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+0xb9b/0x2140 kernel/locking/lockdep.c:3909 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746 autofs_write fs/autofs/waitq.c:55 [inline] autofs_notify_daemon+0x735/0xe50 fs/autofs/waitq.c:164 autofs_wait+0x11dc/0x1870 fs/autofs/waitq.c:426 autofs_mount_wait+0x16b/0x330 fs/autofs/root.c:255 autofs_d_automount+0x393/0x720 fs/autofs/root.c:401 follow_automount fs/namei.c:1455 [inline] __traverse_mounts+0x308/0x5b0 fs/namei.c:1500 traverse_mounts fs/namei.c:1529 [inline] handle_mounts fs/namei.c:1632 [inline] step_into+0x534/0xf30 fs/namei.c:1976 lookup_last fs/namei.c:2636 [inline] path_lookupat+0x163/0x430 fs/namei.c:2660 filename_lookup+0x212/0x570 fs/namei.c:2689 kern_path+0x35/0x50 fs/namei.c:2822 lookup_bdev+0xc0/0x280 block/bdev.c:1205 resume_store+0x169/0x460 kernel/power/hibernate.c:1248 kernfs_fop_write_iter+0x378/0x4f0 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x54b/0xa90 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &sbi->pipe_mutex --> &pipe->mutex --> &of->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&of->mutex); lock(&pipe->mutex); lock(&of->mutex); lock(&sbi->pipe_mutex); *** DEADLOCK *** 4 locks held by syz.7.4441/24880: #0: ffff88807ba32ef8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213 #1: ffff888030082420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #1: ffff888030082420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680 #2: ffff888065042088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 #3: ffff8881416e3878 (kn->active#66){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326 stack backtrace: CPU: 1 UID: 0 PID: 24880 Comm: syz.7.4441 Not tainted 6.15.0-rc5-syzkaller-00158-g3013c33dcbd9 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2079 check_noncircular+0x134/0x160 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+0xb9b/0x2140 kernel/locking/lockdep.c:3909 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746 autofs_write fs/autofs/waitq.c:55 [inline] autofs_notify_daemon+0x735/0xe50 fs/autofs/waitq.c:164 autofs_wait+0x11dc/0x1870 fs/autofs/waitq.c:426 autofs_mount_wait+0x16b/0x330 fs/autofs/root.c:255 autofs_d_automount+0x393/0x720 fs/autofs/root.c:401 follow_automount fs/namei.c:1455 [inline] __traverse_mounts+0x308/0x5b0 fs/namei.c:1500 traverse_mounts fs/namei.c:1529 [inline] handle_mounts fs/namei.c:1632 [inline] step_into+0x534/0xf30 fs/namei.c:1976 lookup_last fs/namei.c:2636 [inline] path_lookupat+0x163/0x430 fs/namei.c:2660 filename_lookup+0x212/0x570 fs/namei.c:2689 kern_path+0x35/0x50 fs/namei.c:2822 lookup_bdev+0xc0/0x280 block/bdev.c:1205 resume_store+0x169/0x460 kernel/power/hibernate.c:1248 kernfs_fop_write_iter+0x378/0x4f0 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x54b/0xa90 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7feb9b98e969 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:00007feb997f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007feb9bbb5fa0 RCX: 00007feb9b98e969 RDX: 0000000000000012 RSI: 0000200000000000 RDI: 0000000000000007 RBP: 00007feb9ba10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007feb9bbb5fa0 R15: 00007ffc4a4a9b78 PM: Image not found (code -6)