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authorJozsef Kadlecsik <kadlec@blackhole.kfki.hu>2016-03-30 11:34:35 +0200
committerPablo Neira Ayuso <pablo@netfilter.org>2016-04-07 18:42:37 +0200
commit644c7e48cb59cfc6988ddc7bf3d3b1ba5fe7fa9d (patch)
treecb2ca7427bab0e28fe097ae6a08acd416c63eccd /net
parentff76def3bd7e816fe0ca7f0840065c566a42ba2f (diff)
downloadlinux-644c7e48cb59cfc6988ddc7bf3d3b1ba5fe7fa9d.tar.bz2
netfilter: nf_conntrack_tcp: Fix stack out of bounds when parsing TCP options
Baozeng Ding reported a KASAN stack out of bounds issue - it uncovered that the TCP option parsing routines in netfilter TCP connection tracking could read one byte out of the buffer of the TCP options. Therefore in the patch we check that the available data length is large enough to parse both TCP option code and size. Reported-by: Baozeng Ding <sploving1@gmail.com> Tested-by: Baozeng Ding <sploving1@gmail.com> Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/nf_conntrack_proto_tcp.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index 278f3b9356ef..7cc1d9c22a9f 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -410,6 +410,8 @@ static void tcp_options(const struct sk_buff *skb,
length--;
continue;
default:
+ if (length < 2)
+ return;
opsize=*ptr++;
if (opsize < 2) /* "silly options" */
return;
@@ -470,6 +472,8 @@ static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
length--;
continue;
default:
+ if (length < 2)
+ return;
opsize = *ptr++;
if (opsize < 2) /* "silly options" */
return;