selinux: fix a missing-check bug in selinux_add_mnt_opt( )

In selinux_add_mnt_opt(), 'val' is allocated by kmemdup_nul(). It returns
NULL when fails. So 'val' should be checked. And 'mnt_opts' should be
freed when error.

Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
Fixes: 757cbe597f ("LSM: new method: ->sb_add_mnt_opt()")
Cc: <stable@vger.kernel.org>
[PM: fixed some indenting problems]
Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Gen Zhang 2019-06-12 21:28:21 +08:00 committed by Paul Moore
parent aff7ed4851
commit e2e0e09758

View File

@ -1052,15 +1052,24 @@ static int selinux_add_mnt_opt(const char *option, const char *val, int len,
if (token == Opt_error)
return -EINVAL;
if (token != Opt_seclabel)
if (token != Opt_seclabel) {
val = kmemdup_nul(val, len, GFP_KERNEL);
if (!val) {
rc = -ENOMEM;
goto free_opt;
}
}
rc = selinux_add_opt(token, val, mnt_opts);
if (unlikely(rc)) {
kfree(val);
if (*mnt_opts) {
selinux_free_mnt_opts(*mnt_opts);
*mnt_opts = NULL;
}
goto free_opt;
}
return rc;
free_opt:
if (*mnt_opts) {
selinux_free_mnt_opts(*mnt_opts);
*mnt_opts = NULL;
}
return rc;
}