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: v3.10.102~83 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=abcb7fb8535f0e7f87150e0ffbeac5a0ff285718;p=thirdparty%2Fkernel%2Fstable.git ipv6: re-enable fragment header matching in ipv6_find_hdr commit 5d150a985520bbe3cb2aa1ceef24a7e32f20c15f upstream. 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: Willy Tarreau --- diff --git a/net/ipv6/exthdrs_core.c b/net/ipv6/exthdrs_core.c index 51af9d0d019a5..f66c1b629582c 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) {