ipv4: Fix crashes in ip_options_compile().

The spec_dst uses should be guarded by skb_rtable() being non-NULL
not just the SKB being non-null.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2012-07-04 16:13:17 -07:00
parent e87183c2b5
commit 11604721a3

View File

@ -253,12 +253,15 @@ int ip_options_compile(struct net *net,
{
__be32 spec_dst = (__force __be32) 0;
unsigned char *pp_ptr = NULL;
struct rtable *rt = NULL;
unsigned char *optptr;
unsigned char *iph;
int optlen, l;
if (skb != NULL) {
spec_dst = fib_compute_spec_dst(skb);
rt = skb_rtable(skb);
if (rt)
spec_dst = fib_compute_spec_dst(skb);
optptr = (unsigned char *)&(ip_hdr(skb)[1]);
} else
optptr = opt->__data;
@ -330,7 +333,7 @@ int ip_options_compile(struct net *net,
pp_ptr = optptr + 2;
goto error;
}
if (skb) {
if (rt) {
memcpy(&optptr[optptr[2]-1], &spec_dst, 4);
opt->is_changed = 1;
}
@ -372,7 +375,7 @@ int ip_options_compile(struct net *net,
goto error;
}
opt->ts = optptr - iph;
if (skb) {
if (rt) {
memcpy(&optptr[optptr[2]-1], &spec_dst, 4);
timeptr = &optptr[optptr[2]+3];
}