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| author | Jordy Zomer <jordy@pwning.systems> | 2021-11-17 20:06:48 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-11-18 11:42:06 +0000 |
| commit | 5f9c55c8066bcd93ac25234a02585701fe2e31df (patch) | |
| tree | 9cfd5b6e77e0bde6d275d7414fb0d321929b9cec | |
| parent | 5d2ca2e12dfb2aff3388ca57b06f570fa6206ced (diff) | |
| download | linux-5f9c55c8066bcd93ac25234a02585701fe2e31df.tar.bz2 | |
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: Jordy Zomer <jordy@pwning.systems>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv6/esp6.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index ed2f061b8768..f0bac6f7ab6b 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -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; |