overlayfs: fs on '.' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: filesystem on './bus' not supported as upperdir ====================================================== overlayfs: fs on './file0' does not support file handles, falling back to index=off. WARNING: possible circular locking dependency detected 4.14.232-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor907/9219 is trying to acquire lock: (sb_writers#3){.+.+}, at: [] sb_start_write include/linux/fs.h:1549 [inline] (sb_writers#3){.+.+}, at: [] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 but task is already holding lock: (&ovl_i_mutex_dir_key[depth]#2){++++}, at: [] inode_lock include/linux/fs.h:719 [inline] (&ovl_i_mutex_dir_key[depth]#2){++++}, at: [] do_last fs/namei.c:3331 [inline] (&ovl_i_mutex_dir_key[depth]#2){++++}, at: [] path_openat+0xde2/0x2970 fs/namei.c:3569 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ( overlayfs: fs on '.' does not support file handles, falling back to index=off. &ovl_i_mutex_dir_key[depth]#2){++++}: down_read+0x36/0x80 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:729 [inline] lookup_slow+0x129/0x400 fs/namei.c:1674 lookup_one_len_unlocked+0x3a0/0x410 fs/namei.c:2595 ovl_lower_positive+0x184/0x350 fs/overlayfs/namei.c:783 overlayfs: maximum fs stacking depth exceeded ovl_rename+0x47c/0xf10 fs/overlayfs/dir.c:968 vfs_rename+0x560/0x1820 fs/namei.c:4496 SYSC_renameat2 fs/namei.c:4644 [inline] SyS_renameat2+0x95b/0xad0 fs/namei.c:4533 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 overlayfs: filesystem on './bus' not supported as upperdir (&oi->lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 ovl_copy_up_start+0x40/0xe0 fs/overlayfs/util.c:318 ovl_copy_up_one+0x21f/0x910 fs/overlayfs/copy_up.c:631 overlayfs: fs on './file0' does not support file handles, falling back to index=off. ovl_copy_up_flags+0xd5/0x120 fs/overlayfs/copy_up.c:686 ovl_rename+0x164/0xf10 fs/overlayfs/dir.c:939 vfs_rename+0x560/0x1820 fs/namei.c:4496 SYSC_renameat2 fs/namei.c:4644 [inline] SyS_renameat2+0x95b/0xad0 fs/namei.c:4533 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb overlayfs: fs on '.' does not support file handles, falling back to index=off. -> #0 (sb_writers#3){.+.+}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 overlayfs: maximum fs stacking depth exceeded percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x64/0x260 fs/super.c:1342 sb_start_write include/linux/fs.h:1549 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 ovl_create_object+0x75/0x1d0 fs/overlayfs/dir.c:538 overlayfs: filesystem on './bus' not supported as upperdir lookup_open+0x77a/0x1750 fs/namei.c:3241 do_last fs/namei.c:3334 [inline] path_openat+0xe08/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb overlayfs: fs on './file0' does not support file handles, falling back to index=off. other info that might help us debug this: Chain exists of: sb_writers#3 overlayfs: fs on '.' does not support file handles, falling back to index=off. --> &oi->lock --> &ovl_i_mutex_dir_key[depth]#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ovl_i_mutex_dir_key[depth]#2); lock(&oi->lock); overlayfs: maximum fs stacking depth exceeded lock(&ovl_i_mutex_dir_key[depth]#2); lock(sb_writers#3); *** DEADLOCK *** 2 locks held by syz-executor907/9219: #0: (sb_writers#10){.+.+}, at: [] sb_start_write include/linux/fs.h:1549 [inline] #0: (sb_writers#10){.+.+}, at: [] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 #1: overlayfs: filesystem on './bus' not supported as upperdir (&ovl_i_mutex_dir_key[depth]#2){++++}, at: [] inode_lock include/linux/fs.h:719 [inline] (&ovl_i_mutex_dir_key[depth]#2){++++}, at: [] do_last fs/namei.c:3331 [inline] (&ovl_i_mutex_dir_key[depth]#2){++++}, at: [] path_openat+0xde2/0x2970 fs/namei.c:3569 stack backtrace: CPU: 1 PID: 9219 Comm: syz-executor907 Not tainted 4.14.232-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x64/0x260 fs/super.c:1342 sb_start_write include/linux/fs.h:1549 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 ovl_create_object+0x75/0x1d0 fs/overlayfs/dir.c:538 lookup_open+0x77a/0x1750 fs/namei.c:3241 do_last fs/namei.c:3334 [inline] path_openat+0xe08/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x4462f9 RSP: 002b:00007fc5725ed2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00000000004cb4d0 RCX: 00000000004462f9 RDX: 00000000004462f9 RSI: 0000000000000000 RDI: 0000000020000080 RBP: 000000000049b06c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e R13: 0079616c7265766f R14: 69662f7375622f2e R15: 00000000004cb4d8 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on '.' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: maximum fs stacking depth exceeded overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: filesystem on './bus' not supported as upperdir overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: fs on '.' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: maximum fs stacking depth exceeded overlayfs: failed to resolve './file1': -2 overlayfs: filesystem on './bus' not supported as upperdir overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on '.' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: filesystem on './bus' not supported as upperdir overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: 'file0' not a directory overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file0': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2