diff options
| author | Jordy Zomer <jordy@pwning.systems> | 2021-11-17 20:06:48 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-08 09:03:19 +0100 |
| commit | 4d5968ea06fbfc7f6bb88dee7ce459f4755cebb5 (patch) | |
| tree | 8167ac0b2a0f99f203f3e1048340ef8cb11ee117 /net | |
| parent | 22519eff7df2d88adcc2568d86046ce1e2b52803 (diff) | |
ipv6: check return value of ipv6_skip_exthdr
[ Upstream commit 5f9c55c8066bcd93ac25234a02585701fe2e31df ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to '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 8d001f665fb1..7f2ffc7b1f75 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; |