====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc7-syzkaller-00117-g448b3fe5a0ea #0 Not tainted ------------------------------------------------------ syz-executor.1/24790 is trying to acquire lock: ffff888011208e80 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb7/0xd60 fs/seq_file.c:182 but task is already holding lock: ffff888054926c68 (&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:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 iter_file_splice_write+0x335/0x14e0 fs/splice.c:687 do_splice_from fs/splice.c:941 [inline] do_splice+0xd77/0x1880 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+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (sb_writers#4){.+.+}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1664 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1800 mnt_want_write+0x3f/0x90 fs/namespace.c:409 ovl_create_object+0x13b/0x370 fs/overlayfs/dir.c:629 lookup_open fs/namei.c:3497 [inline] open_last_lookups fs/namei.c:3566 [inline] path_openat+0x1425/0x3240 fs/namei.c:3796 do_filp_open+0x235/0x490 fs/namei.c:3826 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406 do_sys_open fs/open.c:1421 [inline] __do_sys_creat fs/open.c:1497 [inline] __se_sys_creat fs/open.c:1491 [inline] __x64_sys_creat+0x123/0x170 fs/open.c:1491 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526 inode_lock_shared include/linux/fs.h:805 [inline] lookup_slow+0x45/0x70 fs/namei.c:1708 walk_component+0x2e1/0x410 fs/namei.c:2004 lookup_last fs/namei.c:2461 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2485 filename_lookup+0x256/0x610 fs/namei.c:2514 kern_path+0x35/0x50 fs/namei.c:2622 lookup_bdev+0xc5/0x290 block/bdev.c:1136 resume_store+0x1a0/0x710 kernel/power/hibernate.c:1235 kernfs_fop_write_iter+0x3a1/0x500 fs/kernfs/file.c:334 call_write_iter include/linux/fs.h:2110 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa84/0xcb0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 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:5754 __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 seq_read_iter+0x3d0/0xd60 fs/seq_file.c:225 call_read_iter include/linux/fs.h:2104 [inline] copy_splice_read+0x662/0xb60 fs/splice.c:365 do_splice_read fs/splice.c:985 [inline] splice_direct_to_actor+0x4b7/0xc90 fs/splice.c:1089 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0x28c/0x3e0 fs/splice.c:1233 do_sendfile+0x56d/0xdc0 fs/read_write.c:1295 __do_sys_sendfile64 fs/read_write.c:1362 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 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:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 seq_read_iter+0xb7/0xd60 fs/seq_file.c:182 proc_reg_read_iter+0x1c3/0x290 fs/proc/inode.c:299 call_read_iter include/linux/fs.h:2104 [inline] copy_splice_read+0x662/0xb60 fs/splice.c:365 do_splice_read fs/splice.c:985 [inline] splice_file_to_pipe+0x299/0x500 fs/splice.c:1295 do_sendfile+0x515/0xdc0 fs/read_write.c:1301 __do_sys_sendfile64 fs/read_write.c:1362 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 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#4 --> &pipe->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pipe->mutex); lock(sb_writers#4); lock(&pipe->mutex); lock(&p->lock); *** DEADLOCK *** 1 lock held by syz-executor.1/24790: #0: ffff888054926c68 (&pipe->mutex){+.+.}-{3:3}, at: splice_file_to_pipe+0x2e/0x500 fs/splice.c:1292 stack backtrace: CPU: 0 PID: 24790 Comm: syz-executor.1 Not tainted 6.9.0-rc7-syzkaller-00117-g448b3fe5a0ea #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 seq_read_iter+0xb7/0xd60 fs/seq_file.c:182 proc_reg_read_iter+0x1c3/0x290 fs/proc/inode.c:299 call_read_iter include/linux/fs.h:2104 [inline] copy_splice_read+0x662/0xb60 fs/splice.c:365 do_splice_read fs/splice.c:985 [inline] splice_file_to_pipe+0x299/0x500 fs/splice.c:1295 do_sendfile+0x515/0xdc0 fs/read_write.c:1301 __do_sys_sendfile64 fs/read_write.c:1362 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0db8e7dd69 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0db9cb90c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f0db8fabf80 RCX: 00007f0db8e7dd69 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000004 RBP: 00007f0db8eca49e R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000f6c1 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f0db8fabf80 R15: 00007ffc05f84598