UPSTREAM: selinux: ensure the policy has been loaded before reading the sidtab stats

Check to make sure we have loaded a policy before we query the
sidtab's hash stats.  Failure to do so could result in a kernel
panic/oops due to a dereferenced NULL pointer.

Fixes: 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
(cherry picked from commit 15b590a81fcdd44ddcb4810f2a6334df8b6ca512)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I9c9309341634ba0bdc6d151ec1ae4040a71dcd40
This commit is contained in:
Paul Moore 2019-12-23 16:38:36 -05:00 committed by Greg Kroah-Hartman
parent b1ab580076
commit 26d0b8dd3a

View File

@ -1261,6 +1261,12 @@ int security_sidtab_hash_stats(struct selinux_state *state, char *page)
{
int rc;
if (!state->initialized) {
pr_err("SELinux: %s: called before initial load_policy\n",
__func__);
return -EINVAL;
}
read_lock(&state->ss->policy_rwlock);
rc = sidtab_hash_stats(state->ss->sidtab, page);
read_unlock(&state->ss->policy_rwlock);