From: Florian Westphal Date: Tue, 1 Mar 2016 15:15:16 +0000 (+0100) Subject: ipv6: re-enable fragment header matching in ipv6_find_hdr X-Git-Tag: firefly_0821_release~176^2~4^2~49^2~101 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b80398d91c2bdb23d503c5d742ba5c4541269112;p=firefly-linux-kernel-4.4.55.git ipv6: re-enable fragment header matching in ipv6_find_hdr [ Upstream commit 5d150a985520bbe3cb2aa1ceef24a7e32f20c15f ] When ipv6_find_hdr is used to find a fragment header (caller specifies target NEXTHDR_FRAGMENT) we erronously return -ENOENT for all fragments with nonzero offset. Before commit 9195bb8e381d, when target was specified, we did not enter the exthdr walk loop as nexthdr == target so this used to work. Now we do (so we can skip empty route headers). When we then stumble upon a frag with nonzero frag_off we must return -ENOENT ("header not found") only if the caller did not specifically request NEXTHDR_FRAGMENT. This allows nfables exthdr expression to match ipv6 fragments, e.g. via nft add rule ip6 filter input frag frag-off gt 0 Fixes: 9195bb8e381d ("ipv6: improve ipv6_find_hdr() to skip empty routing headers") Signed-off-by: Florian Westphal Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/ipv6/exthdrs_core.c b/net/ipv6/exthdrs_core.c index 5c5d23e59da5..9508a20fbf61 100644 --- a/net/ipv6/exthdrs_core.c +++ b/net/ipv6/exthdrs_core.c @@ -257,7 +257,11 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, *fragoff = _frag_off; return hp->nexthdr; } - return -ENOENT; + if (!found) + return -ENOENT; + if (fragoff) + *fragoff = _frag_off; + break; } hdrlen = 8; } else if (nexthdr == NEXTHDR_AUTH) {