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authorHannes Frederic Sowa <hannes@stressinduktion.org>2014-05-11 23:01:13 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-05-31 13:20:38 -0700
commit65117efb2b65ef69c1c243b63296142164d152ee (patch)
parentadeb3fe4ef6621793d7f1d6f0b9c9cc88827c5b7 (diff)
ipv6: fix calculation of option len in ip6_append_data
[ Upstream commit 3a1cebe7e05027a1c96f2fc1a8eddf5f19b78f42 ] tot_len does specify the size of struct ipv6_txoptions. We need opt_flen + opt_nflen to calculate the overall length of additional ipv6 extensions. I found this while auditing the ipv6 output path for a memory corruption reported by Alexey Preobrazhensky while he fuzzed an instrumented AddressSanitizer kernel with trinity. This may or may not be the cause of the original bug. Fixes: 4df98e76cde7c6 ("ipv6: pmtudisc setting not respected with UFO/CORK") Reported-by: Alexey Preobrazhensky <preobr@google.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 264a984ae16d..a62b610307ec 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1229,7 +1229,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
unsigned int maxnonfragsize, headersize;
headersize = sizeof(struct ipv6hdr) +
- (opt ? opt->tot_len : 0) +
+ (opt ? opt->opt_flen + opt->opt_nflen : 0) +
(dst_allfrag(&rt->dst) ?
sizeof(struct frag_hdr) : 0) +