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xfrm4: Properly handle unsupported protocols

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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>
This commit is contained in:
Steffen Klassert 2014-04-29 07:50:44 +02:00
parent a32452366b
commit 61622cc6f2
1 changed files with 17 additions and 2 deletions
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19
net/ipv4/xfrm4_protocol.c
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@ -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);