====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.2.728/10529 is trying to acquire lock: ffff0000d5c21880 (&of->mutex){+.+.}-{4:4}, at: kernfs_seq_start+0x54/0x164 fs/kernfs/file.c:172 but task is already holding lock: ffff0000d390ce18 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb0/0xbe8 fs/seq_file.c:183 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&p->lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x164/0xed0 kernel/locking/mutex.c:820 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:873 seq_read_iter+0xb0/0xbe8 fs/seq_file.c:183 copy_splice_read+0x4b8/0x8fc fs/splice.c:362 do_splice_read+0x1c4/0x2e8 fs/splice.c:980 splice_file_to_pipe+0x84/0xd4 fs/splice.c:1290 do_sendfile+0x3b8/0x6c0 fs/read_write.c:1378 __do_sys_sendfile64 fs/read_write.c:1433 [inline] __se_sys_sendfile64 fs/read_write.c:1419 [inline] __arm64_sys_sendfile64+0x1bc/0x284 fs/read_write.c:1419 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x19c/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 -> #3 (&pipe->mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x164/0xed0 kernel/locking/mutex.c:820 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:873 pipe_lock+0x64/0x88 fs/pipe.c:91 iter_file_splice_write+0x184/0xd50 fs/splice.c:682 do_splice_from fs/splice.c:936 [inline] do_splice+0x9c0/0x1228 fs/splice.c:1349 __do_splice fs/splice.c:1431 [inline] __do_sys_splice fs/splice.c:1634 [inline] __se_sys_splice fs/splice.c:1616 [inline] __arm64_sys_splice+0x2c0/0x4e4 fs/splice.c:1616 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 -> #2 (sb_writers#5){.+.+}-{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/super.h:19 [inline] sb_start_write+0x5c/0x294 include/linux/fs/super.h:125 mnt_want_write+0x44/0x9c fs/namespace.c:493 ovl_want_write+0x90/0xa0 fs/overlayfs/util.c:38 ovl_setattr+0x238/0x4ac fs/overlayfs/inode.c:75 notify_change+0x928/0xb7c fs/attr.c:556 chown_common+0x39c/0x548 fs/open.c:776 vfs_fchown+0xb4/0x108 fs/open.c:841 ksys_fchown+0x50/0x9c fs/open.c:853 __do_sys_fchown fs/open.c:858 [inline] __se_sys_fchown fs/open.c:856 [inline] __arm64_sys_fchown+0x7c/0x94 fs/open.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 -> #1 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}: down_read+0x58/0x2bc kernel/locking/rwsem.c:1568 inode_lock_shared include/linux/fs.h:1044 [inline] lookup_slow+0x50/0x84 fs/namei.c:1931 walk_component fs/namei.c:2278 [inline] lookup_last fs/namei.c:2785 [inline] path_lookupat+0x358/0x798 fs/namei.c:2809 filename_lookup+0x1d0/0x3c8 fs/namei.c:2838 kern_path+0x4c/0x70 fs/namei.c:3044 lookup_bdev+0xc0/0x248 block/bdev.c:1213 resume_store+0x120/0x3e4 kernel/power/hibernate.c:1306 kobj_attr_store+0x6c/0x90 lib/kobject.c:840 sysfs_kf_write+0xe0/0x108 fs/sysfs/file.c:142 kernfs_fop_write_iter+0x260/0x3b8 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x51c/0xa0c fs/read_write.c:688 ksys_write+0x12c/0x228 fs/read_write.c:740 __do_sys_write fs/read_write.c:751 [inline] __se_sys_write fs/read_write.c:748 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:748 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 -> #0 (&of->mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x17c0/0x2ebc kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x364 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x164/0xed0 kernel/locking/mutex.c:820 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:873 kernfs_seq_start+0x54/0x164 fs/kernfs/file.c:172 traverse+0x154/0x4a4 fs/seq_file.c:107 seq_read_iter+0xb00/0xbe8 fs/seq_file.c:196 kernfs_fop_read_iter+0x13c/0x414 fs/kernfs/file.c:297 copy_splice_read+0x4b8/0x8fc fs/splice.c:362 do_splice_read+0x1c4/0x2e8 fs/splice.c:980 splice_direct_to_actor+0x20c/0x7a8 fs/splice.c:1084 do_splice_direct_actor+0x140/0x228 fs/splice.c:1202 do_splice_direct+0x58/0x70 fs/splice.c:1228 vfs_copy_file_range+0x6c4/0xcf0 fs/read_write.c:1634 __do_sys_copy_file_range fs/read_write.c:1683 [inline] __se_sys_copy_file_range fs/read_write.c:1650 [inline] __arm64_sys_copy_file_range+0x318/0x5d4 fs/read_write.c:1650 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 other info that might help us debug this: Chain exists of: &of->mutex --> &pipe->mutex --> &p->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&p->lock); lock(&pipe->mutex); lock(&p->lock); lock(&of->mutex); *** DEADLOCK *** 1 lock held by syz.2.728/10529: #0: ffff0000d390ce18 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb0/0xbe8 fs/seq_file.c:183 stack backtrace: CPU: 0 UID: 0 PID: 10529 Comm: syz.2.728 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/02/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 print_circular_bug+0x328/0x330 kernel/locking/lockdep.c:2043 check_noncircular+0x158/0x174 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x17c0/0x2ebc kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x364 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x164/0xed0 kernel/locking/mutex.c:820 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:873 kernfs_seq_start+0x54/0x164 fs/kernfs/file.c:172 traverse+0x154/0x4a4 fs/seq_file.c:107 seq_read_iter+0xb00/0xbe8 fs/seq_file.c:196 kernfs_fop_read_iter+0x13c/0x414 fs/kernfs/file.c:297 copy_splice_read+0x4b8/0x8fc fs/splice.c:362 do_splice_read+0x1c4/0x2e8 fs/splice.c:980 splice_direct_to_actor+0x20c/0x7a8 fs/splice.c:1084 do_splice_direct_actor+0x140/0x228 fs/splice.c:1202 do_splice_direct+0x58/0x70 fs/splice.c:1228 vfs_copy_file_range+0x6c4/0xcf0 fs/read_write.c:1634 __do_sys_copy_file_range fs/read_write.c:1683 [inline] __se_sys_copy_file_range fs/read_write.c:1650 [inline] __arm64_sys_copy_file_range+0x318/0x5d4 fs/read_write.c:1650 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594