====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc5-syzkaller-00322-gb9021de3ec2f #0 Not tainted ------------------------------------------------------ syz.6.2159/14377 is trying to acquire lock: ffff88802fb81e80 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb4/0xd70 fs/seq_file.c:182 but task is already holding lock: ffff88805c1ae468 (&pipe->mutex){+.+.}-{3:3}, at: splice_file_to_pipe+0x2e/0x500 fs/splice.c:1292 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&pipe->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 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 -> #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_create_object+0x13a/0x3a0 fs/overlayfs/dir.c:642 lookup_open fs/namei.c:3595 [inline] open_last_lookups fs/namei.c:3694 [inline] path_openat+0x1c03/0x3590 fs/namei.c:3930 do_filp_open+0x235/0x490 fs/namei.c:3960 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_creat fs/open.c:1508 [inline] __se_sys_creat fs/open.c:1502 [inline] __x64_sys_creat+0x123/0x170 fs/open.c:1502 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_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 traverse+0x14f/0x550 fs/seq_file.c:106 seq_read_iter+0xc8c/0xd70 fs/seq_file.c:195 copy_splice_read+0x663/0xb60 fs/splice.c:365 do_splice_read fs/splice.c:985 [inline] splice_direct_to_actor+0x4af/0xc80 fs/splice.c:1089 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0x289/0x3e0 fs/splice.c:1233 do_sendfile+0x561/0xe10 fs/read_write.c:1388 __do_sys_sendfile64 fs/read_write.c:1449 [inline] __se_sys_sendfile64+0x100/0x1e0 fs/read_write.c:1441 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 (&p->lock){+.+.}-{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 seq_read_iter+0xb4/0xd70 fs/seq_file.c:182 proc_reg_read_iter+0x1c2/0x290 fs/proc/inode.c:299 copy_splice_read+0x663/0xb60 fs/splice.c:365 do_splice_read fs/splice.c:985 [inline] splice_file_to_pipe+0x290/0x500 fs/splice.c:1295 do_sendfile+0x509/0xe10 fs/read_write.c:1394 __do_sys_sendfile64 fs/read_write.c:1455 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1441 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: &p->lock --> sb_writers#5 --> &pipe->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pipe->mutex); lock(sb_writers#5); lock(&pipe->mutex); lock(&p->lock); *** DEADLOCK *** 1 lock held by syz.6.2159/14377: #0: ffff88805c1ae468 (&pipe->mutex){+.+.}-{3:3}, at: splice_file_to_pipe+0x2e/0x500 fs/splice.c:1292 stack backtrace: CPU: 0 UID: 0 PID: 14377 Comm: syz.6.2159 Not tainted 6.12.0-rc5-syzkaller-00322-gb9021de3ec2f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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 seq_read_iter+0xb4/0xd70 fs/seq_file.c:182 proc_reg_read_iter+0x1c2/0x290 fs/proc/inode.c:299 copy_splice_read+0x663/0xb60 fs/splice.c:365 do_splice_read fs/splice.c:985 [inline] splice_file_to_pipe+0x290/0x500 fs/splice.c:1295 do_sendfile+0x509/0xe10 fs/read_write.c:1394 __do_sys_sendfile64 fs/read_write.c:1455 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1441 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: 0033:0x7f07d877e719 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:00007f07d9492038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f07d8936058 RCX: 00007f07d877e719 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001 RBP: 00007f07d87f132e R08: 0000000000000000 R09: 0000000000000000 R10: 4000000000010042 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f07d8936058 R15: 00007ffd77ed0318