====================================================== WARNING: possible circular locking dependency detected 6.10.0-rc5-syzkaller-00155-g66e55ff12e73 #0 Not tainted ------------------------------------------------------ syz.2.1818/11922 is trying to acquire lock: ffff88803d074c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x281/0x500 fs/kernfs/file.c:325 but task is already holding lock: ffff88802d7a3868 (&pipe->mutex){+.+.}-{3:3}, at: pipe_lock fs/pipe.c:92 [inline] ffff88802d7a3868 (&pipe->mutex){+.+.}-{3:3}, at: pipe_lock+0x64/0x80 fs/pipe.c:89 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&pipe->mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 pipe_lock fs/pipe.c:92 [inline] pipe_lock+0x64/0x80 fs/pipe.c:89 iter_file_splice_write+0x1f0/0x10b0 fs/splice.c:687 do_splice_from fs/splice.c:941 [inline] do_splice+0x148c/0x1f90 fs/splice.c:1354 __do_splice+0x327/0x360 fs/splice.c:1436 __do_sys_splice fs/splice.c:1652 [inline] __se_sys_splice fs/splice.c:1634 [inline] __x64_sys_splice+0x1d2/0x260 fs/splice.c:1634 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (sb_writers#5){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1655 [inline] sb_start_write include/linux/fs.h:1791 [inline] mnt_want_write+0x6f/0x450 fs/namespace.c:409 ovl_set_or_remove_acl fs/overlayfs/inode.c:517 [inline] ovl_set_acl+0x518/0xa00 fs/overlayfs/inode.c:566 set_posix_acl+0x25c/0x320 fs/posix_acl.c:955 vfs_set_acl+0x53d/0x940 fs/posix_acl.c:1134 do_set_acl+0x15a/0x1b0 fs/posix_acl.c:1279 do_setxattr+0xeb/0x170 fs/xattr.c:626 setxattr+0x15d/0x180 fs/xattr.c:652 path_setxattr+0x179/0x1e0 fs/xattr.c:671 __do_sys_lsetxattr fs/xattr.c:694 [inline] __se_sys_lsetxattr fs/xattr.c:690 [inline] __x64_sys_lsetxattr+0xc1/0x160 fs/xattr.c:690 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&ovl_i_mutex_dir_key[depth]#2){++++}-{3:3}: down_read+0x9a/0x330 kernel/locking/rwsem.c:1526 inode_lock_shared include/linux/fs.h:801 [inline] lookup_slow fs/namei.c:1708 [inline] walk_component+0x342/0x5b0 fs/namei.c:2004 lookup_last fs/namei.c:2469 [inline] path_lookupat+0x17f/0x770 fs/namei.c:2493 filename_lookup+0x1e5/0x5b0 fs/namei.c:2522 kern_path+0x35/0x50 fs/namei.c:2630 lookup_bdev+0xd9/0x280 block/bdev.c:1157 resume_store+0x1d8/0x460 kernel/power/hibernate.c:1235 kobj_attr_store+0x55/0x80 lib/kobject.c:840 sysfs_kf_write+0x117/0x170 fs/sysfs/file.c:136 kernfs_fop_write_iter+0x343/0x500 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6b6/0x1140 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&of->mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 kernfs_fop_write_iter+0x281/0x500 fs/kernfs/file.c:325 iter_file_splice_write+0x906/0x10b0 fs/splice.c:743 do_splice_from fs/splice.c:941 [inline] do_splice+0x148c/0x1f90 fs/splice.c:1354 __do_splice+0x327/0x360 fs/splice.c:1436 __do_sys_splice fs/splice.c:1652 [inline] __se_sys_splice fs/splice.c:1634 [inline] __x64_sys_splice+0x1d2/0x260 fs/splice.c:1634 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &of->mutex --> sb_writers#5 --> &pipe->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pipe->mutex); lock(sb_writers#5); lock(&pipe->mutex); lock(&of->mutex); *** DEADLOCK *** 2 locks held by syz.2.1818/11922: #0: ffff888024784420 (sb_writers#9){.+.+}-{0:0}, at: __do_splice+0x327/0x360 fs/splice.c:1436 #1: ffff88802d7a3868 (&pipe->mutex){+.+.}-{3:3}, at: pipe_lock fs/pipe.c:92 [inline] #1: ffff88802d7a3868 (&pipe->mutex){+.+.}-{3:3}, at: pipe_lock+0x64/0x80 fs/pipe.c:89 stack backtrace: CPU: 2 PID: 11922 Comm: syz.2.1818 Not tainted 6.10.0-rc5-syzkaller-00155-g66e55ff12e73 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 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 kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 kernfs_fop_write_iter+0x281/0x500 fs/kernfs/file.c:325 iter_file_splice_write+0x906/0x10b0 fs/splice.c:743 do_splice_from fs/splice.c:941 [inline] do_splice+0x148c/0x1f90 fs/splice.c:1354 __do_splice+0x327/0x360 fs/splice.c:1436 __do_sys_splice fs/splice.c:1652 [inline] __se_sys_splice fs/splice.c:1634 [inline] __x64_sys_splice+0x1d2/0x260 fs/splice.c:1634 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5821175b29 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:00007f5821e78048 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007f5821304070 RCX: 00007f5821175b29 RDX: 0000000000000006 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007f58211f6756 R08: 000000000000bfd1 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f5821304070 R15: 00007ffda6f8dbe8