overlayfs: ...falling back to uuid=null. ====================================================== WARNING: possible circular locking dependency detected 6.8.0-rc7-syzkaller-00229-g10d48d70e82d #0 Not tainted ------------------------------------------------------ syz-executor.1/12423 is trying to acquire lock: ffff88803cf50420 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409 but task is already holding lock: ffff8880377ac160 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] ffff8880377ac160 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: open_last_lookups fs/namei.c:3566 [inline] ffff8880377ac160 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: path_openat+0x7d2/0x3240 fs/namei.c:3799 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}: lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526 inode_lock_shared include/linux/fs.h:814 [inline] lookup_slow+0x45/0x70 fs/namei.c:1709 walk_component+0x2e1/0x410 fs/namei.c:2005 lookup_last fs/namei.c:2462 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2486 filename_lookup+0x255/0x610 fs/namei.c:2515 kern_path+0x35/0x50 fs/namei.c:2623 lookup_bdev+0xc5/0x290 block/bdev.c:1014 resume_store+0x1a0/0x710 kernel/power/hibernate.c:1183 kernfs_fop_write_iter+0x3a4/0x500 fs/kernfs/file.c:334 call_write_iter include/linux/fs.h:2087 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa81/0xcb0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 -> #3 (&of->mutex){+.+.}-{3:3}: lock_acquire+0x1e3/0x530 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:2081 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x978/0xb70 fs/read_write.c:476 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 -> #2 (&p->lock){+.+.}-{3:3}: lock_acquire+0x1e3/0x530 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 call_read_iter include/linux/fs.h:2081 [inline] copy_splice_read+0x661/0xb60 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:1356 [inline] __se_sys_sendfile64+0x100/0x1e0 fs/read_write.c:1348 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 -> #1 (&pipe->mutex/1){+.+.}-{3:3}: lock_acquire+0x1e3/0x530 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_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 -> #0 (sb_writers#23){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1641 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1777 mnt_want_write+0x3f/0x90 fs/namespace.c:409 ovl_create_object+0x13b/0x370 fs/overlayfs/dir.c:629 lookup_open fs/namei.c:3500 [inline] open_last_lookups fs/namei.c:3569 [inline] path_openat+0x1424/0x3240 fs/namei.c:3799 do_filp_open+0x234/0x490 fs/namei.c:3829 do_sys_openat2+0x13e/0x1d0 fs/open.c:1404 do_sys_open fs/open.c:1419 [inline] __do_sys_open fs/open.c:1427 [inline] __se_sys_open fs/open.c:1423 [inline] __x64_sys_open+0x225/0x270 fs/open.c:1423 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 other info that might help us debug this: Chain exists of: sb_writers#23 --> &of->mutex --> &ovl_i_mutex_dir_key[depth] Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ovl_i_mutex_dir_key[depth]); lock(&of->mutex); lock(&ovl_i_mutex_dir_key[depth]); rlock(sb_writers#23); *** DEADLOCK *** 2 locks held by syz-executor.1/12423: #0: ffff888037870420 (sb_writers#21){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409 #1: ffff8880377ac160 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #1: ffff8880377ac160 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: open_last_lookups fs/namei.c:3566 [inline] #1: ffff8880377ac160 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: path_openat+0x7d2/0x3240 fs/namei.c:3799 stack backtrace: CPU: 1 PID: 12423 Comm: syz-executor.1 Not tainted 6.8.0-rc7-syzkaller-00229-g10d48d70e82d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 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+0x18ca/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1641 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1777 mnt_want_write+0x3f/0x90 fs/namespace.c:409 ovl_create_object+0x13b/0x370 fs/overlayfs/dir.c:629 lookup_open fs/namei.c:3500 [inline] open_last_lookups fs/namei.c:3569 [inline] path_openat+0x1424/0x3240 fs/namei.c:3799 do_filp_open+0x234/0x490 fs/namei.c:3829 do_sys_openat2+0x13e/0x1d0 fs/open.c:1404 do_sys_open fs/open.c:1419 [inline] __do_sys_open fs/open.c:1427 [inline] __se_sys_open fs/open.c:1423 [inline] __x64_sys_open+0x225/0x270 fs/open.c:1423 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7ff0ede7dda9 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:00007ff0eeccd0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ff0edfabf80 RCX: 00007ff0ede7dda9 RDX: 0000000000000000 RSI: 0000000000060142 RDI: 0000000020000000 RBP: 00007ff0edeca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007ff0edfabf80 R15: 00007ffd899a8388