BUG: memory leak
unreferenced object 0xffff88800d2d0c60 (size 16):
  comm "syz-executor.1", pid 14337, jiffies 4296813535 (age 18.955s)
  hex dump (first 16 bytes):
    28 c8 bb 20 80 88 ff ff 00 c0 fa 42 80 88 ff ff  (.. .......B....
  backtrace:
    [<000000003ace2927>] kmalloc include/linux/slab.h:552 [inline]
    [<000000003ace2927>] ext4_multi_mount_protect+0x861/0xb20 fs/ext4/mmp.c:367
    [<000000006673b181>] ext4_fill_super+0xa20e/0xcf20 fs/ext4/super.c:4774
    [<0000000019a19194>] mount_bdev+0x331/0x3f0 fs/super.c:1419
    [<000000003ff1b2d2>] legacy_get_tree+0x105/0x220 fs/fs_context.c:592
    [<000000008c6031a5>] vfs_get_tree+0x8e/0x2f0 fs/super.c:1549
    [<00000000222a12d3>] do_new_mount fs/namespace.c:2881 [inline]
    [<00000000222a12d3>] path_mount+0x139a/0x2080 fs/namespace.c:3211
    [<000000009aa17f24>] do_mount fs/namespace.c:3224 [inline]
    [<000000009aa17f24>] __do_sys_mount fs/namespace.c:3432 [inline]
    [<000000009aa17f24>] __se_sys_mount fs/namespace.c:3409 [inline]
    [<000000009aa17f24>] __x64_sys_mount+0x27e/0x300 fs/namespace.c:3409
    [<0000000083d7b2b8>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
    [<00000000e9a3ad04>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: leak checking failed