path: root/include/net/ipv6.h
diff options
authorGeorg Kohmann <geokohma@cisco.com>2020-11-11 12:50:25 +0100
committerJakub Kicinski <kuba@kernel.org>2020-11-16 10:15:11 -0800
commit9d9e937b1c8be97b424e3e11938e183fcde905c0 (patch)
tree4c351d9384371d390054c973c38347f594740b5a /include/net/ipv6.h
parentMerge branch 'fix-usage-counter-leak-by-adding-a-general-sync-ops' (diff)
ipv6/netfilter: Discard first fragment not including all headers
Packets are processed even though the first fragment don't include all headers through the upper layer header. This breaks TAHI IPv6 Core Conformance Test v6LC.1.3.6. Referring to RFC8200 SECTION 4.5: "If the first fragment does not include all headers through an Upper-Layer header, then that fragment should be discarded and an ICMP Parameter Problem, Code 3, message should be sent to the source of the fragment, with the Pointer field set to zero." The fragment needs to be validated the same way it is done in commit 2efdaaaf883a ("IPv6: reply ICMP error if the first fragment don't include all headers") for ipv6. Wrap the validation into a common function, ipv6_frag_thdr_truncated() to check for truncation in the upper layer header. This validation does not fullfill all aspects of RFC 8200, section 4.5, but is at the moment sufficient to pass mentioned TAHI test. In netfilter, utilize the fragment offset returned by find_prev_fhdr() to let ipv6_frag_thdr_truncated() start it's traverse from the fragment header. Return 0 to drop the fragment in the netfilter. This is the same behaviour as used on other protocol errors in this function, e.g. when nf_ct_frag6_queue() returns -EPROTO. The Fragment will later be picked up by ipv6_frag_rcv() in reassembly.c. ipv6_frag_rcv() will then send an appropriate ICMP Parameter Problem message back to the source. References commit 2efdaaaf883a ("IPv6: reply ICMP error if the first fragment don't include all headers") Signed-off-by: Georg Kohmann <geokohma@cisco.com> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org> Link: https://lore.kernel.org/r/20201111115025.28879-1-geokohma@cisco.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to '')
1 files changed, 2 insertions, 0 deletions
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index bd1f396cc9c7..637cc6dd12b7 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -1064,6 +1064,8 @@ int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
bool ipv6_ext_hdr(u8 nexthdr);
+bool ipv6_frag_thdr_truncated(struct sk_buff *skb, int start, u8 *nexthdrp);
enum {
IP6_FH_F_FRAG = (1 << 0),
IP6_FH_F_AUTH = (1 << 1),