====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc7-syzkaller-00070-g0a9b9d17f3a7 #0 Not tainted ------------------------------------------------------ syz.6.1424/12927 is trying to acquire lock: ffff88802435d868 (&pipe->mutex){+.+.}-{3:3}, at: iter_file_splice_write+0x330/0x1510 fs/splice.c:687 but task is already holding lock: ffff88807f976420 (sb_writers#5){.+.+}-{0:0}, at: do_splice+0xce4/0x18e0 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:5825 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1716 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1852 mnt_want_write+0x3f/0x90 fs/namespace.c:515 ovl_fix_origin fs/overlayfs/namei.c:908 [inline] ovl_lookup+0x1394/0x2a60 fs/overlayfs/namei.c:1143 __lookup_slow+0x28c/0x3f0 fs/namei.c:1732 lookup_slow+0x53/0x70 fs/namei.c:1749 walk_component+0x2e1/0x410 fs/namei.c:2053 lookup_last fs/namei.c:2556 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2580 filename_lookup+0x256/0x610 fs/namei.c:2609 user_path_at+0x3a/0x60 fs/namei.c:3016 __do_sys_name_to_handle_at fs/fhandle.c:123 [inline] __se_sys_name_to_handle_at+0x119/0x8b0 fs/fhandle.c:106 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]#2){++++}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524 inode_lock_shared include/linux/fs.h:825 [inline] lookup_slow+0x45/0x70 fs/namei.c:1748 walk_component+0x2e1/0x410 fs/namei.c:2053 lookup_last fs/namei.c:2556 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2580 filename_lookup+0x256/0x610 fs/namei.c:2609 kern_path+0x35/0x50 fs/namei.c:2717 lookup_bdev+0xc5/0x290 block/bdev.c:1164 resume_store+0x1a0/0x710 kernel/power/hibernate.c:1239 kernfs_fop_write_iter+0x3a0/0x500 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:590 [inline] vfs_write+0xaeb/0xd30 fs/read_write.c:683 ksys_write+0x183/0x2b0 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){+.+.}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 kernfs_fop_write_iter+0x1ea/0x500 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+0xd68/0x18e0 fs/splice.c:1354 __do_splice fs/splice.c:1436 [inline] __do_sys_splice fs/splice.c:1652 [inline] __se_sys_splice+0x331/0x4a0 fs/splice.c:1634 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){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 iter_file_splice_write+0x330/0x1510 fs/splice.c:687 do_splice_from fs/splice.c:941 [inline] do_splice+0xd68/0x18e0 fs/splice.c:1354 __do_splice fs/splice.c:1436 [inline] __do_sys_splice fs/splice.c:1652 [inline] __se_sys_splice+0x331/0x4a0 fs/splice.c:1634 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]#2 --> sb_writers#5 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_writers#5); lock(&ovl_i_mutex_dir_key[depth]#2); lock(sb_writers#5); lock(&pipe->mutex); *** DEADLOCK *** 1 lock held by syz.6.1424/12927: #0: ffff88807f976420 (sb_writers#5){.+.+}-{0:0}, at: do_splice+0xce4/0x18e0 fs/splice.c:1353 stack backtrace: CPU: 1 UID: 0 PID: 12927 Comm: syz.6.1424 Not tainted 6.12.0-rc7-syzkaller-00070-g0a9b9d17f3a7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 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:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 iter_file_splice_write+0x330/0x1510 fs/splice.c:687 do_splice_from fs/splice.c:941 [inline] do_splice+0xd68/0x18e0 fs/splice.c:1354 __do_splice fs/splice.c:1436 [inline] __do_sys_splice fs/splice.c:1652 [inline] __se_sys_splice+0x331/0x4a0 fs/splice.c:1634 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: 0033:0x7efd0db7e719 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:00007efd0e905038 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007efd0dd36058 RCX: 00007efd0db7e719 RDX: 0000000000000006 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007efd0dbf175e R08: 0000000000001000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007efd0dd36058 R15: 00007ffcfccbb578