====================================================== WARNING: possible circular locking dependency detected 6.11.0-rc6-syzkaller-00308-gb31c44928842 #0 Not tainted ------------------------------------------------------ syz.0.571/10510 is trying to acquire lock: ffff888065736420 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 but task is already holding lock: ffff88805de73b38 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: inode_lock include/linux/fs.h:800 [inline] ffff88805de73b38 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: open_last_lookups fs/namei.c:3644 [inline] ffff88805de73b38 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: path_openat+0x7fb/0x3470 fs/namei.c:3883 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+0x1ed/0x550 kernel/locking/lockdep.c:5759 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526 inode_lock_shared include/linux/fs.h:810 [inline] lookup_slow+0x45/0x70 fs/namei.c:1734 walk_component+0x2e1/0x410 fs/namei.c:2039 lookup_last fs/namei.c:2542 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2566 filename_lookup+0x256/0x610 fs/namei.c:2595 kern_path+0x35/0x50 fs/namei.c:2703 lookup_bdev+0xc5/0x290 block/bdev.c:1157 resume_store+0x1a0/0x710 kernel/power/hibernate.c:1235 kernfs_fop_write_iter+0x3a1/0x500 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa72/0xc90 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+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&of->mutex){+.+.}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __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+0xc5e/0xd60 fs/seq_file.c:195 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+0x515/0xe20 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+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&p->lock){+.+.}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __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 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+0x515/0xe20 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+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&pipe->mutex){+.+.}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __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+0xd77/0x1900 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 (sb_writers#5 ){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1676 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1812 mnt_want_write+0x3f/0x90 fs/namespace.c:515 ovl_create_object+0x13b/0x370 fs/overlayfs/dir.c:642 lookup_open fs/namei.c:3578 [inline] open_last_lookups fs/namei.c:3647 [inline] path_openat+0x1a9a/0x3470 fs/namei.c:3883 do_filp_open+0x235/0x490 fs/namei.c:3913 do_sys_openat2+0x13e/0x1d0 fs/open.c:1416 do_sys_open fs/open.c:1431 [inline] __do_sys_creat fs/open.c:1507 [inline] __se_sys_creat fs/open.c:1501 [inline] __x64_sys_creat+0x123/0x170 fs/open.c:1501 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: sb_writers#5 --> &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#5); *** DEADLOCK *** 2 locks held by syz.0.571/10510: #0: ffff888023f38420 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff88805de73b38 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: inode_lock include/linux/fs.h:800 [inline] #1: ffff88805de73b38 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: open_last_lookups fs/namei.c:3644 [inline] #1: ffff88805de73b38 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: path_openat+0x7fb/0x3470 fs/namei.c:3883 stack backtrace: CPU: 0 UID: 0 PID: 10510 Comm: syz.0.571 Not tainted 6.11.0-rc6-syzkaller-00308-gb31c44928842 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186 check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1676 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1812 mnt_want_write+0x3f/0x90 fs/namespace.c:515 ovl_create_object+0x13b/0x370 fs/overlayfs/dir.c:642 lookup_open fs/namei.c:3578 [inline] open_last_lookups fs/namei.c:3647 [inline] path_openat+0x1a9a/0x3470 fs/namei.c:3883 do_filp_open+0x235/0x490 fs/namei.c:3913 do_sys_openat2+0x13e/0x1d0 fs/open.c:1416 do_sys_open fs/open.c:1431 [inline] __do_sys_creat fs/open.c:1507 [inline] __se_sys_creat fs/open.c:1501 [inline] __x64_sys_creat+0x123/0x170 fs/open.c:1501 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: 0033:0x7fb30f77cef9 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:00007fb3104d6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007fb30f936058 RCX: 00007fb30f77cef9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000100 RBP: 00007fb30f7ef046 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb30f936058 R15: 00007fffff90dd88