====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc2-syzkaller-00048-gc62f4b82d571 #0 Not tainted ------------------------------------------------------ syz.0.595/8298 is trying to acquire lock: ffff888028e1c140 (&sbi->pipe_mutex){+.+.}-{4:4}, at: autofs_write fs/autofs/waitq.c:55 [inline] ffff888028e1c140 (&sbi->pipe_mutex){+.+.}-{4:4}, at: autofs_notify_daemon+0x86b/0x1100 fs/autofs/waitq.c:164 but task is already holding lock: ffff88801e6a8c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 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}: lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746 kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 seq_read_iter+0x3f1/0xda0 fs/seq_file.c:225 copy_splice_read+0x63f/0xb50 fs/splice.c:363 do_splice_read fs/splice.c:979 [inline] splice_file_to_pipe+0x290/0x500 fs/splice.c:1289 do_sendfile+0x526/0x8c0 fs/read_write.c:1374 __do_sys_sendfile64 fs/read_write.c:1429 [inline] __se_sys_sendfile64+0x17e/0x1e0 fs/read_write.c:1415 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&p->lock){+.+.}-{4:4}: lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746 seq_read_iter+0xb4/0xda0 fs/seq_file.c:182 copy_splice_read+0x63f/0xb50 fs/splice.c:363 do_splice_read fs/splice.c:979 [inline] splice_file_to_pipe+0x290/0x500 fs/splice.c:1289 do_sendfile+0x526/0x8c0 fs/read_write.c:1374 __do_sys_sendfile64 fs/read_write.c:1429 [inline] __se_sys_sendfile64+0x17e/0x1e0 fs/read_write.c:1415 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&pipe->mutex){+.+.}-{4:4}: lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746 anon_pipe_write+0x167/0x14f0 fs/pipe.c:459 __kernel_write_iter+0x4c0/0x990 fs/read_write.c:617 __kernel_write+0x122/0x180 fs/read_write.c:637 autofs_write fs/autofs/waitq.c:57 [inline] autofs_notify_daemon+0x87e/0x1100 fs/autofs/waitq.c:164 autofs_wait+0x1324/0x1dd0 fs/autofs/waitq.c:426 autofs_mount_wait+0x170/0x330 fs/autofs/root.c:255 autofs_d_automount+0x555/0x710 fs/autofs/root.c:401 follow_automount fs/namei.c:1455 [inline] __traverse_mounts+0x2b5/0x580 fs/namei.c:1500 traverse_mounts fs/namei.c:1529 [inline] handle_mounts fs/namei.c:1632 [inline] step_into+0x5bd/0x1000 fs/namei.c:1966 lookup_last fs/namei.c:2626 [inline] path_lookupat+0x169/0x440 fs/namei.c:2650 filename_lookup+0x290/0x670 fs/namei.c:2679 user_path_at+0x3a/0x60 fs/namei.c:3085 user_statfs fs/statfs.c:103 [inline] __do_sys_statfs fs/statfs.c:193 [inline] __se_sys_statfs+0xdc/0x220 fs/statfs.c:190 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 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+0xa69/0x24e0 kernel/locking/lockdep.c:3909 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746 autofs_write fs/autofs/waitq.c:55 [inline] autofs_notify_daemon+0x86b/0x1100 fs/autofs/waitq.c:164 autofs_wait+0x1324/0x1dd0 fs/autofs/waitq.c:426 autofs_mount_wait+0x170/0x330 fs/autofs/root.c:255 autofs_d_automount+0x555/0x710 fs/autofs/root.c:401 follow_automount fs/namei.c:1455 [inline] __traverse_mounts+0x2b5/0x580 fs/namei.c:1500 traverse_mounts fs/namei.c:1529 [inline] handle_mounts fs/namei.c:1632 [inline] step_into+0x5bd/0x1000 fs/namei.c:1966 lookup_last fs/namei.c:2626 [inline] path_lookupat+0x169/0x440 fs/namei.c:2650 filename_lookup+0x290/0x670 fs/namei.c:2679 kern_path+0x35/0x50 fs/namei.c:2787 lookup_bdev+0xc8/0x290 block/bdev.c:1167 resume_store+0x1e1/0x720 kernel/power/hibernate.c:1248 kernfs_fop_write_iter+0x398/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x70f/0xd10 fs/read_write.c:684 ksys_write+0x19d/0x2d0 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 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 --> &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.0.595/8298: #0: ffff8880602a1278 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x310 fs/file.c:1213 #1: ffff888035f64420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #1: ffff888035f64420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #2: ffff88801e6a8c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #3: ffff88801f6edc38 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 stack backtrace: CPU: 1 UID: 0 PID: 8298 Comm: syz.0.595 Not tainted 6.15.0-rc2-syzkaller-00048-gc62f4b82d571 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2079 check_noncircular+0x142/0x160 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+0xa69/0x24e0 kernel/locking/lockdep.c:3909 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746 autofs_write fs/autofs/waitq.c:55 [inline] autofs_notify_daemon+0x86b/0x1100 fs/autofs/waitq.c:164 autofs_wait+0x1324/0x1dd0 fs/autofs/waitq.c:426 autofs_mount_wait+0x170/0x330 fs/autofs/root.c:255 autofs_d_automount+0x555/0x710 fs/autofs/root.c:401 follow_automount fs/namei.c:1455 [inline] __traverse_mounts+0x2b5/0x580 fs/namei.c:1500 traverse_mounts fs/namei.c:1529 [inline] handle_mounts fs/namei.c:1632 [inline] step_into+0x5bd/0x1000 fs/namei.c:1966 lookup_last fs/namei.c:2626 [inline] path_lookupat+0x169/0x440 fs/namei.c:2650 filename_lookup+0x290/0x670 fs/namei.c:2679 kern_path+0x35/0x50 fs/namei.c:2787 lookup_bdev+0xc8/0x290 block/bdev.c:1167 resume_store+0x1e1/0x720 kernel/power/hibernate.c:1248 kernfs_fop_write_iter+0x398/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x70f/0xd10 fs/read_write.c:684 ksys_write+0x19d/0x2d0 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe7ef38e169 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:00007fe7f0118038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fe7ef5b6080 RCX: 00007fe7ef38e169 RDX: 0000000000000012 RSI: 0000200000000040 RDI: 0000000000000004 RBP: 00007fe7ef410a68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe7ef5b6080 R15: 00007fff1f198af8 block device autoloading is deprecated and will be removed. syz.0.595: attempt to access beyond end of device md0: rw=2048, sector=0, nr_sectors = 8 limit=0 PM: Image not found (code -5)