xfrm4: Properly handle unsupported protocols
We don't catch the case if an unsupported protocol is submitted
to the xfrm4 protocol handlers, this can lead to NULL pointer
dereferences. Fix this by adding the appropriate checks.
Fixes: 3328715e ("xfrm4: Add IPsec protocol multiplexer")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/ipv4/xfrm4_protocol.c b/net/ipv4/xfrm4_protocol.c
index 7f7b243..a2ce010 100644
--- a/net/ipv4/xfrm4_protocol.c
+++ b/net/ipv4/xfrm4_protocol.c
@@ -50,8 +50,12 @@
{
int ret;
struct xfrm4_protocol *handler;
+ struct xfrm4_protocol __rcu **head = proto_handlers(protocol);
- for_each_protocol_rcu(*proto_handlers(protocol), handler)
+ if (!head)
+ return 0;
+
+ for_each_protocol_rcu(*head, handler)
if ((ret = handler->cb_handler(skb, err)) <= 0)
return ret;
@@ -64,15 +68,20 @@
{
int ret;
struct xfrm4_protocol *handler;
+ struct xfrm4_protocol __rcu **head = proto_handlers(nexthdr);
XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
XFRM_SPI_SKB_CB(skb)->family = AF_INET;
XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
- for_each_protocol_rcu(*proto_handlers(nexthdr), handler)
+ if (!head)
+ goto out;
+
+ for_each_protocol_rcu(*head, handler)
if ((ret = handler->input_handler(skb, nexthdr, spi, encap_type)) != -EINVAL)
return ret;
+out:
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
kfree_skb(skb);
@@ -208,6 +217,9 @@
int ret = -EEXIST;
int priority = handler->priority;
+ if (!proto_handlers(protocol) || !netproto(protocol))
+ return -EINVAL;
+
mutex_lock(&xfrm4_protocol_mutex);
if (!rcu_dereference_protected(*proto_handlers(protocol),
@@ -250,6 +262,9 @@
struct xfrm4_protocol *t;
int ret = -ENOENT;
+ if (!proto_handlers(protocol) || !netproto(protocol))
+ return -EINVAL;
+
mutex_lock(&xfrm4_protocol_mutex);
for (pprev = proto_handlers(protocol);