====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc3-next-20250218-syzkaller #0 Not tainted ------------------------------------------------------ syz.4.3088/17565 is trying to acquire lock: ffff88806d49c468 (&pipe->mutex){+.+.}-{4:4}, at: iter_file_splice_write+0x330/0x1510 fs/splice.c:687 but task is already holding lock: ffff88801c28a420 (sb_writers#5){.+.+}-{0:0}, at: do_splice+0xce4/0x18b0 fs/splice.c:1353 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (sb_writers#5){.+.+}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1783 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1919 mnt_want_write+0x3f/0x90 fs/namespace.c:556 ovl_create_object+0x13a/0x3a0 fs/overlayfs/dir.c:656 lookup_open fs/namei.c:3659 [inline] open_last_lookups fs/namei.c:3758 [inline] path_openat+0x1954/0x35b0 fs/namei.c:3994 do_filp_open+0x282/0x4e0 fs/namei.c:4024 do_sys_openat2+0x13f/0x1c0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524 inode_lock_shared include/linux/fs.h:877 [inline] lookup_slow+0x45/0x70 fs/namei.c:1815 walk_component+0x2eb/0x410 fs/namei.c:2120 lookup_last fs/namei.c:2618 [inline] path_lookupat+0x169/0x440 fs/namei.c:2642 filename_lookup+0x2a6/0x670 fs/namei.c:2671 kern_path+0x35/0x50 fs/namei.c:2779 lookup_bdev+0xc5/0x290 block/bdev.c:1163 resume_store+0x1a0/0x710 kernel/power/hibernate.c:1247 kernfs_fop_write_iter+0x3a5/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:591 [inline] vfs_write+0xacf/0xd10 fs/read_write.c:684 ksys_write+0x18f/0x2b0 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&of->mutex){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 kernfs_fop_write_iter+0x1ef/0x510 fs/kernfs/file.c:325 iter_file_splice_write+0xbfa/0x1510 fs/splice.c:743 do_splice_from fs/splice.c:941 [inline] do_splice+0xd68/0x18b0 fs/splice.c:1354 __do_splice fs/splice.c:1436 [inline] __do_sys_splice fs/splice.c:1639 [inline] __se_sys_splice+0x2e0/0x450 fs/splice.c:1621 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&pipe->mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 iter_file_splice_write+0x330/0x1510 fs/splice.c:687 do_splice_from fs/splice.c:941 [inline] do_splice+0xd68/0x18b0 fs/splice.c:1354 __do_splice fs/splice.c:1436 [inline] __do_sys_splice fs/splice.c:1639 [inline] __se_sys_splice+0x2e0/0x450 fs/splice.c:1621 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &pipe->mutex --> &ovl_i_mutex_dir_key[depth] --> sb_writers#5 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_writers#5); lock(&ovl_i_mutex_dir_key[depth]); lock(sb_writers#5); lock(&pipe->mutex); *** DEADLOCK *** 1 lock held by syz.4.3088/17565: #0: ffff88801c28a420 (sb_writers#5){.+.+}-{0:0}, at: do_splice+0xce4/0x18b0 fs/splice.c:1353 stack backtrace: CPU: 0 UID: 0 PID: 17565 Comm: syz.4.3088 Not tainted 6.14.0-rc3-next-20250218-syzkaller #0 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+0x13a/0x1b0 kernel/locking/lockdep.c:2076 check_noncircular+0x36a/0x4a0 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+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 iter_file_splice_write+0x330/0x1510 fs/splice.c:687 do_splice_from fs/splice.c:941 [inline] do_splice+0xd68/0x18b0 fs/splice.c:1354 __do_splice fs/splice.c:1436 [inline] __do_sys_splice fs/splice.c:1639 [inline] __se_sys_splice+0x2e0/0x450 fs/splice.c:1621 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb57d98d169 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:00007fb57e7b2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007fb57dba5fa0 RCX: 00007fb57d98d169 RDX: 0000000000000009 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007fb57da0e2a0 R08: 0000000000200002 R09: 0800000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb57dba5fa0 R15: 00007fffaf3c8eb8