selinux: ensure we cleanup the internal AVC counters on error in avc_insert()

Fix avc_insert() to call avc_node_kill() if we've already allocated
an AVC node and the code fails to insert the node in the cache.

Fixes: fa1aa143ac ("selinux: extended permissions for ioctls")
Reported-by: rsiddoji@codeaurora.org
Suggested-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Paul Moore 2019-12-09 20:39:46 -05:00
parent b2104ac0bd
commit d8db60cb23

View File

@ -617,40 +617,37 @@ static struct avc_node *avc_insert(struct selinux_avc *avc,
struct avc_node *pos, *node = NULL;
int hvalue;
unsigned long flag;
spinlock_t *lock;
struct hlist_head *head;
if (avc_latest_notif_update(avc, avd->seqno, 1))
goto out;
return NULL;
node = avc_alloc_node(avc);
if (node) {
struct hlist_head *head;
spinlock_t *lock;
int rc = 0;
if (!node)
return NULL;
hvalue = avc_hash(ssid, tsid, tclass);
avc_node_populate(node, ssid, tsid, tclass, avd);
rc = avc_xperms_populate(node, xp_node);
if (rc) {
kmem_cache_free(avc_node_cachep, node);
return NULL;
}
head = &avc->avc_cache.slots[hvalue];
lock = &avc->avc_cache.slots_lock[hvalue];
spin_lock_irqsave(lock, flag);
hlist_for_each_entry(pos, head, list) {
if (pos->ae.ssid == ssid &&
pos->ae.tsid == tsid &&
pos->ae.tclass == tclass) {
avc_node_replace(avc, node, pos);
goto found;
}
}
hlist_add_head_rcu(&node->list, head);
found:
spin_unlock_irqrestore(lock, flag);
avc_node_populate(node, ssid, tsid, tclass, avd);
if (avc_xperms_populate(node, xp_node)) {
avc_node_kill(avc, node);
return NULL;
}
out:
hvalue = avc_hash(ssid, tsid, tclass);
head = &avc->avc_cache.slots[hvalue];
lock = &avc->avc_cache.slots_lock[hvalue];
spin_lock_irqsave(lock, flag);
hlist_for_each_entry(pos, head, list) {
if (pos->ae.ssid == ssid &&
pos->ae.tsid == tsid &&
pos->ae.tclass == tclass) {
avc_node_replace(avc, node, pos);
goto found;
}
}
hlist_add_head_rcu(&node->list, head);
found:
spin_unlock_irqrestore(lock, flag);
return node;
}