BUG: memory leak
unreferenced object 0xffff88801621bee0 (size 16):
  comm "syz-executor.7", pid 8750, jiffies 4295616685 (age 17.718s)
  hex dump (first 16 bytes):
    80 3e c7 45 80 88 ff ff 00 80 74 43 80 88 ff ff  .>.E......tC....
  backtrace:
    [<000000002128357a>] kmalloc include/linux/slab.h:552 [inline]
    [<000000002128357a>] ext4_multi_mount_protect+0x861/0xb20 fs/ext4/mmp.c:367
    [<00000000319c9630>] ext4_fill_super+0xa20e/0xcf20 fs/ext4/super.c:4774
    [<0000000076b97a16>] mount_bdev+0x331/0x3f0 fs/super.c:1419
    [<0000000023d31a0a>] legacy_get_tree+0x105/0x220 fs/fs_context.c:592
    [<00000000bbb7d726>] vfs_get_tree+0x8e/0x2f0 fs/super.c:1549
    [<00000000eedbc531>] do_new_mount fs/namespace.c:2881 [inline]
    [<00000000eedbc531>] path_mount+0x139a/0x2080 fs/namespace.c:3211
    [<00000000d12ffc7e>] do_mount fs/namespace.c:3224 [inline]
    [<00000000d12ffc7e>] __do_sys_mount fs/namespace.c:3432 [inline]
    [<00000000d12ffc7e>] __se_sys_mount fs/namespace.c:3409 [inline]
    [<00000000d12ffc7e>] __x64_sys_mount+0x27e/0x300 fs/namespace.c:3409
    [<000000007b9be1c9>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
    [<00000000ede9f986>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: leak checking failed