====================================================== WARNING: possible circular locking dependency detected 6.16.0-rc2-syzkaller-00087-g24770983ccfe #0 Not tainted ------------------------------------------------------ syz.9.5701/26421 is trying to acquire lock: ffff888076918cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:884 [inline] ffff888076918cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}, at: lookup_slow fs/namei.c:1833 [inline] ffff888076918cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}, at: walk_component+0x345/0x5b0 fs/namei.c:2138 but task is already holding lock: ffff888028cf8888 (&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:602 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:747 kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 iter_file_splice_write+0x91c/0x1150 fs/splice.c:738 do_splice_from fs/splice.c:935 [inline] do_splice+0x1475/0x1fc0 fs/splice.c:1348 __do_splice+0x32a/0x360 fs/splice.c:1430 __do_sys_splice fs/splice.c:1633 [inline] __se_sys_splice fs/splice.c:1615 [inline] __x64_sys_splice+0x187/0x250 fs/splice.c:1615 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&pipe->mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:747 pipe_lock fs/pipe.c:91 [inline] pipe_lock+0x64/0x80 fs/pipe.c:88 iter_file_splice_write+0x1ea/0x1150 fs/splice.c:683 do_splice_from fs/splice.c:935 [inline] do_splice+0x1475/0x1fc0 fs/splice.c:1348 __do_splice+0x32a/0x360 fs/splice.c:1430 __do_sys_splice fs/splice.c:1633 [inline] __se_sys_splice fs/splice.c:1615 [inline] __x64_sys_splice+0x187/0x250 fs/splice.c:1615 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (sb_writers#6){.+.+}-{0:0}: percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs.h:1795 [inline] sb_start_write include/linux/fs.h:1931 [inline] mnt_want_write+0x6f/0x450 fs/namespace.c:557 ovl_create_object+0x12c/0x300 fs/overlayfs/dir.c:628 lookup_open.isra.0+0x11d3/0x1580 fs/namei.c:3717 open_last_lookups fs/namei.c:3816 [inline] path_openat+0x893/0x2cb0 fs/namei.c:4052 do_filp_open+0x20b/0x470 fs/namei.c:4082 do_sys_openat2+0x11b/0x1d0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_open fs/open.c:1460 [inline] __se_sys_open fs/open.c:1456 [inline] __x64_sys_open+0x153/0x1e0 fs/open.c:1456 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}: check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain kernel/locking/lockdep.c:3911 [inline] __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240 lock_acquire kernel/locking/lockdep.c:5871 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828 down_read+0x9b/0x480 kernel/locking/rwsem.c:1524 inode_lock_shared include/linux/fs.h:884 [inline] lookup_slow fs/namei.c:1833 [inline] walk_component+0x345/0x5b0 fs/namei.c:2138 link_path_walk+0x627/0xe20 fs/namei.c:2506 path_lookupat+0x15a/0x6d0 fs/namei.c:2662 filename_lookup+0x224/0x5f0 fs/namei.c:2692 kern_path+0x35/0x50 fs/namei.c:2825 lookup_bdev+0xd8/0x280 block/bdev.c:1205 resume_store+0x1d6/0x460 kernel/power/hibernate.c:1272 kobj_attr_store+0x55/0x80 lib/kobject.c:840 sysfs_kf_write+0xef/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x354/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6c4/0x1150 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 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: &ovl_i_mutex_dir_key[depth] --> &pipe->mutex --> &of->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&of->mutex); lock(&pipe->mutex); lock(&of->mutex); rlock(&ovl_i_mutex_dir_key[depth]); *** DEADLOCK *** 4 locks held by syz.9.5701/26421: #0: ffff88802562c9b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1217 #1: ffff8880367a6428 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #2: ffff888028cf8888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 #3: ffff888140434878 (kn->active#61){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326 stack backtrace: CPU: 1 UID: 0 PID: 26421 Comm: syz.9.5701 Not tainted 6.16.0-rc2-syzkaller-00087-g24770983ccfe #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __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:2046 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain kernel/locking/lockdep.c:3911 [inline] __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240 lock_acquire kernel/locking/lockdep.c:5871 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828 down_read+0x9b/0x480 kernel/locking/rwsem.c:1524 inode_lock_shared include/linux/fs.h:884 [inline] lookup_slow fs/namei.c:1833 [inline] walk_component+0x345/0x5b0 fs/namei.c:2138 link_path_walk+0x627/0xe20 fs/namei.c:2506 path_lookupat+0x15a/0x6d0 fs/namei.c:2662 filename_lookup+0x224/0x5f0 fs/namei.c:2692 kern_path+0x35/0x50 fs/namei.c:2825 lookup_bdev+0xd8/0x280 block/bdev.c:1205 resume_store+0x1d6/0x460 kernel/power/hibernate.c:1272 kobj_attr_store+0x55/0x80 lib/kobject.c:840 sysfs_kf_write+0xef/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x354/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6c4/0x1150 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb9d778e929 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:00007fb9d865e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fb9d79b6080 RCX: 00007fb9d778e929 RDX: 000000000000002b RSI: 0000200000000ec0 RDI: 0000000000000008 RBP: 00007fb9d7810b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb9d79b6080 R15: 00007ffe34141928