====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc1-syzkaller-00235-g9946eaf552b1 #0 Not tainted ------------------------------------------------------ syz.1.3077/17425 is trying to acquire lock: ffff888031217888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x27b/0x500 fs/kernfs/file.c:325 but task is already holding lock: ffff888033ef9068 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock fs/pipe.c:92 [inline] ffff888033ef9068 (&pipe->mutex){+.+.}-{4:4}, 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){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 pipe_lock fs/pipe.c:92 [inline] pipe_lock+0x64/0x80 fs/pipe.c:89 iter_file_splice_write+0x1eb/0x10b0 fs/splice.c:687 do_splice_from fs/splice.c:941 [inline] do_splice+0x146a/0x1f70 fs/splice.c:1354 __do_splice+0x327/0x360 fs/splice.c:1436 __do_sys_splice fs/splice.c:1639 [inline] __se_sys_splice fs/splice.c:1621 [inline] __x64_sys_splice+0x187/0x250 fs/splice.c:1621 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#6){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1785 [inline] sb_start_write include/linux/fs.h:1921 [inline] mnt_want_write+0x6f/0x450 fs/namespace.c:547 ovl_rename+0x7f5/0x1890 fs/overlayfs/dir.c:1171 vfs_rename+0xf88/0x21f0 fs/namei.c:5069 do_renameat2+0xc5f/0xdd0 fs/namei.c:5226 __do_sys_renameat2 fs/namei.c:5260 [inline] __se_sys_renameat2 fs/namei.c:5257 [inline] __x64_sys_renameat2+0xe7/0x130 fs/namei.c:5257 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]){++++}-{4:4}: down_read+0x9a/0x330 kernel/locking/rwsem.c:1524 inode_lock_shared include/linux/fs.h:887 [inline] lookup_slow fs/namei.c:1809 [inline] walk_component+0x342/0x5b0 fs/namei.c:2114 lookup_last fs/namei.c:2612 [inline] path_lookupat+0x17f/0x770 fs/namei.c:2636 filename_lookup+0x221/0x5f0 fs/namei.c:2665 kern_path+0x35/0x50 fs/namei.c:2773 lookup_bdev+0xd9/0x280 block/bdev.c:1163 resume_store+0x1d8/0x460 kernel/power/hibernate.c:1247 kobj_attr_store+0x55/0x80 lib/kobject.c:840 sysfs_kf_write+0x117/0x170 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x33d/0x500 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x5ae/0x1150 fs/read_write.c:679 ksys_write+0x12b/0x250 fs/read_write.c:731 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){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 kernfs_fop_write_iter+0x27b/0x500 fs/kernfs/file.c:325 iter_file_splice_write+0x90f/0x10b0 fs/splice.c:743 do_splice_from fs/splice.c:941 [inline] do_splice+0x146a/0x1f70 fs/splice.c:1354 __do_splice+0x327/0x360 fs/splice.c:1436 __do_sys_splice fs/splice.c:1639 [inline] __se_sys_splice fs/splice.c:1621 [inline] __x64_sys_splice+0x187/0x250 fs/splice.c:1621 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#6 --> &pipe->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pipe->mutex); lock(sb_writers#6); lock(&pipe->mutex); lock(&of->mutex); *** DEADLOCK *** 2 locks held by syz.1.3077/17425: #0: ffff888036542420 (sb_writers#9){.+.+}-{0:0}, at: __do_splice+0x327/0x360 fs/splice.c:1436 #1: ffff888033ef9068 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock fs/pipe.c:92 [inline] #1: ffff888033ef9068 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock+0x64/0x80 fs/pipe.c:89 stack backtrace: CPU: 1 UID: 0 PID: 17425 Comm: syz.1.3077 Not tainted 6.14.0-rc1-syzkaller-00235-g9946eaf552b1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x490/0x760 kernel/locking/lockdep.c:2076 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2208 check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 kernfs_fop_write_iter+0x27b/0x500 fs/kernfs/file.c:325 iter_file_splice_write+0x90f/0x10b0 fs/splice.c:743 do_splice_from fs/splice.c:941 [inline] do_splice+0x146a/0x1f70 fs/splice.c:1354 __do_splice+0x327/0x360 fs/splice.c:1436 __do_sys_splice fs/splice.c:1639 [inline] __se_sys_splice fs/splice.c:1621 [inline] __x64_sys_splice+0x187/0x250 fs/splice.c:1621 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: 0033:0x7f6f8c78cde9 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:00007f6f8a5f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007f6f8c9a6160 RCX: 00007f6f8c78cde9 RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f6f8c80e2a0 R08: 000000000000bfd1 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f6f8c9a6160 R15: 00007ffd0edf53c8