BUG: memory leak
unreferenced object 0xffff88803594ace0 (size 16):
  comm "syz-executor.6", pid 10689, jiffies 4295737674 (age 16.355s)
  hex dump (first 16 bytes):
    58 a6 ba 20 80 88 ff ff 00 a0 6d 0f 80 88 ff ff  X.. ......m.....
  backtrace:
    [<00000000d395b1ce>] kmalloc include/linux/slab.h:552 [inline]
    [<00000000d395b1ce>] ext4_multi_mount_protect+0x861/0xb20 fs/ext4/mmp.c:367
    [<000000001a6adc58>] ext4_fill_super+0xa20e/0xcf20 fs/ext4/super.c:4774
    [<00000000a789b265>] mount_bdev+0x331/0x3f0 fs/super.c:1419
    [<00000000889f61ec>] legacy_get_tree+0x105/0x220 fs/fs_context.c:592
    [<0000000072f98d72>] vfs_get_tree+0x8e/0x2f0 fs/super.c:1549
    [<000000001bf3c9fd>] do_new_mount fs/namespace.c:2881 [inline]
    [<000000001bf3c9fd>] path_mount+0x139a/0x2080 fs/namespace.c:3211
    [<0000000023eeb817>] do_mount fs/namespace.c:3224 [inline]
    [<0000000023eeb817>] __do_sys_mount fs/namespace.c:3432 [inline]
    [<0000000023eeb817>] __se_sys_mount fs/namespace.c:3409 [inline]
    [<0000000023eeb817>] __x64_sys_mount+0x27e/0x300 fs/namespace.c:3409
    [<000000006af8184f>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
    [<00000000ca1c46f4>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: leak checking failed