Commit 5f9c55c8 authored by Jordy Zomer's avatar Jordy Zomer Committed by David S. Miller
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ipv6: check return value of ipv6_skip_exthdr 



The offset value is used in pointer math on skb->data.
Since ipv6_skip_exthdr may return -1 the pointer to uh and th
may not point to the actual udp and tcp headers and potentially
overwrite other stuff. This is why I think this should be checked.

EDIT:  added {}'s, thanks Kees

Signed-off-by: default avatarJordy Zomer <jordy@pwning.systems>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5d2ca2e1

net/ipv6/esp6.c

+6 −0
Original line number Diff line number Diff line
@@ -808,6 +808,12 @@ int esp6_input_done2(struct sk_buff *skb, int err) 
		struct tcphdr *th;



		offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);



		if (offset < 0) {

			err = -EINVAL;

			goto out;

		}



		uh = (void *)(skb->data + offset);

		th = (void *)(skb->data + offset);

		hdr_len += offset;