[IPCOMP]: Fetch nexthdr before ipch is destroyed

When I moved the nexthdr setting out of IPComp I accidently moved
the reading of ipch->nexthdr after the decompression.  Unfortunately
this means that we'd be reading from a stale ipch pointer which
doesn't work very well.

This patch moves the reading up so that we get the correct nexthdr
value.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/ipcomp.c b/net/ipv4/ipcomp.c
index f4af99a..b79cdbe 100644 (file)
--- a/net/ipv4/ipcomp.c
+++ b/net/ipv4/ipcomp.c
@@ -74,6 +74,7 @@ out:
 
 static int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
 {
+       int nexthdr;
        int err = -ENOMEM;
        struct ip_comp_hdr *ipch;
 
@@ -84,13 +85,15 @@ static int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
 
        /* Remove ipcomp header and decompress original payload */
        ipch = (void *)skb->data;
+       nexthdr = ipch->nexthdr;
+
        skb->transport_header = skb->network_header + sizeof(*ipch);
        __skb_pull(skb, sizeof(*ipch));
        err = ipcomp_decompress(x, skb);
        if (err)
                goto out;
 
-       err = ipch->nexthdr;
+       err = nexthdr;
 
 out:
        return err;

diff --git a/net/ipv6/ipcomp6.c b/net/ipv6/ipcomp6.c
index b276d04..710325e 100644 (file)
--- a/net/ipv6/ipcomp6.c
+++ b/net/ipv6/ipcomp6.c
@@ -64,6 +64,7 @@ static LIST_HEAD(ipcomp6_tfms_list);
 
 static int ipcomp6_input(struct xfrm_state *x, struct sk_buff *skb)
 {
+       int nexthdr;
        int err = -ENOMEM;
        struct ip_comp_hdr *ipch;
        int plen, dlen;
@@ -79,6 +80,8 @@ static int ipcomp6_input(struct xfrm_state *x, struct sk_buff *skb)
 
        /* Remove ipcomp header and decompress original payload */
        ipch = (void *)skb->data;
+       nexthdr = ipch->nexthdr;
+
        skb->transport_header = skb->network_header + sizeof(*ipch);
        __skb_pull(skb, sizeof(*ipch));
 
@@ -108,7 +111,7 @@ static int ipcomp6_input(struct xfrm_state *x, struct sk_buff *skb)
        skb->truesize += dlen - plen;
        __skb_put(skb, dlen - plen);
        skb_copy_to_linear_data(skb, scratch, dlen);
-       err = ipch->nexthdr;
+       err = nexthdr;
 
 out_put_cpu:
        put_cpu();