BUG: memory leak
unreferenced object 0xffff88810641db80 (size 32):
  comm "syz-executor.6", pid 8273, jiffies 4295046573 (age 9.570s)
  hex dump (first 32 bytes):
    34 32 39 35 30 34 36 35 37 33 00 00 00 00 00 00  4295046573......
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000a4316e12>] kmalloc include/linux/slab.h:555 [inline]
    [<00000000a4316e12>] v9fs_random_cachetag fs/9p/cache.c:36 [inline]
    [<00000000a4316e12>] v9fs_cache_session_get_cookie+0x98/0x100 fs/9p/cache.c:52
    [<00000000c8495a35>] v9fs_session_init+0x5a1/0x840 fs/9p/v9fs.c:470
    [<0000000036152bfe>] v9fs_mount+0x56/0x390 fs/9p/vfs_super.c:124
    [<00000000f55c97a4>] legacy_get_tree+0x26/0x70 fs/fs_context.c:592
    [<00000000748ce749>] vfs_get_tree+0x28/0xe0 fs/super.c:1547
    [<00000000af8dfd06>] do_new_mount fs/namespace.c:2875 [inline]
    [<00000000af8dfd06>] do_mount+0xa63/0xe40 fs/namespace.c:3200
    [<00000000acdc3309>] __do_sys_mount fs/namespace.c:3410 [inline]
    [<00000000acdc3309>] __se_sys_mount fs/namespace.c:3387 [inline]
    [<00000000acdc3309>] __x64_sys_mount+0xb0/0x120 fs/namespace.c:3387
    [<0000000054127a2a>] do_syscall_64+0x4c/0xe0 arch/x86/entry/common.c:384
    [<000000000cb27deb>] entry_SYSCALL_64_after_hwframe+0x44/0xa9