loop5: rw=2049, want=45112, limit=40427 overlayfs: upper fs does not support tmpfile. overlayfs: failed to create directory ./file1/index (errno: 30); mounting read-only ===================================== WARNING: bad unlock balance detected! 4.14.305-syzkaller #0 Not tainted ------------------------------------- syz-executor.5/10487 is trying to release lock (sb_writers) at: [] ovl_workdir_create.cold+0xeb/0xf7 fs/overlayfs/super.c:546 but there are no more locks to release! other info that might help us debug this: 1 lock held by syz-executor.5/10487: #0: (&type->s_umount_key#57/1){+.+.}, at: [] alloc_super fs/super.c:251 [inline] #0: (&type->s_umount_key#57/1){+.+.}, at: [] sget_userns+0x556/0xc10 fs/super.c:516 stack backtrace: CPU: 0 PID: 10487 Comm: syz-executor.5 Not tainted 4.14.305-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_unlock_imbalance_bug include/trace/events/lock.h:58 [inline] __lock_release kernel/locking/lockdep.c:3769 [inline] lock_release.cold+0x70/0xbf kernel/locking/lockdep.c:4017 ovl_workdir_create.cold+0xeb/0xf7 fs/overlayfs/super.c:546 ovl_fill_super+0x2498/0x2610 fs/overlayfs/super.c:1084 mount_nodev+0x4c/0xf0 fs/super.c:1180 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2572 [inline] do_mount+0xe65/0x2a30 fs/namespace.c:2905 SYSC_mount fs/namespace.c:3121 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3098 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 RIP: 0033:0x7f4d6e12c0f9 RSP: 002b:00007f4d6c69e168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f4d6e24bf80 RCX: 00007f4d6e12c0f9 RDX: 0000000020000080 RSI: 0000000020000040 RDI: 0000000000000000 RBP: 00007f4d6e187ae9 R08: 0000000020000340 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc23168f7f R14: 00007f4d6c69e300 R15: 0000000000022000 overlayfs: try deleting index dir or mounting with '-o index=off' to disable inodes index. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 8018 at fs/namespace.c:1178 cleanup_mnt+0x222/0x2c0 fs/namespace.c:1178