Re: [PATCH v3] selinux: lsm: fix a missing-check bug in selinux_sb_eat_lsm_opts()

[Al Viro]

On Sat, Jun 01, 2019 at 10:15:26AM +0800, Gen Zhang wrote:
> In selinux_sb_eat_lsm_opts(), 'arg' is allocated by kmemdup_nul(). It
> returns NULL when fails. So 'arg' should be checked. And 'mnt_opts' 
> should be freed when error.

What's the latter one for?  On failure we'll get to put_fs_context()
pretty soon, so
        security_free_mnt_opts(&fc->security);
will be called just fine.  Leaving it allocated on failure is fine...