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>
diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
index 766dfe56..1f02251 100644
--- a/net/ipv4/ip_options.c
+++ b/net/ipv4/ip_options.c
@@ -253,12 +253,15 @@
{
__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 @@
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 @@
goto error;
}
opt->ts = optptr - iph;
- if (skb) {
+ if (rt) {
memcpy(&optptr[optptr[2]-1], &spec_dst, 4);
timeptr = &optptr[optptr[2]+3];
}