OpenE2K
/
linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ipv6: fix calculation of option len in ip6_append_data 

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: 4df98e76cd ("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>
This commit is contained in:
Hannes Frederic Sowa 2014-05-11 23:01:13 +02:00 committed by David S. Miller
parent 3d4405226d
commit 3a1cebe7e0
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
net/ipv6/ip6_output.c
View File

@ -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) +
rt->rt6i_nfheader_len;