@@ -50,8 +50,12 @@ int xfrm4_rcv_cb(struct sk_buff *skb, u8 protocol, int err)
{
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 xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi,
{
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 xfrm4_protocol_register(struct xfrm4_protocol *handler,
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 @@ int xfrm4_protocol_deregister(struct xfrm4_protocol *handler,
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);
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> --- net/ipv4/xfrm4_protocol.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)