From: Eric Dumazet <edumazet@google.com>
Date: Fri, 3 Feb 2017 08:03:26 +0000 (-0800)
Subject: netlabel: out of bound access in cipso_v4_validate()
X-Git-Tag: v3.2.87~70
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=530bcee641bd3729f6dc7c36e265df11997fcf54;ds=sidebyside

netlabel: out of bound access in cipso_v4_validate()

commit d71b7896886345c53ef1d84bda2bc758554f5d61 upstream.

syzkaller found another out of bound access in ip_options_compile(),
or more exactly in cipso_v4_validate()

Fixes: 20e2a8648596 ("cipso: handle CIPSO options correctly when NetLabel is disabled")
Fixes: 446fda4f2682 ("[NetLabel]: CIPSOv4 engine")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov  <dvyukov@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/include/net/cipso_ipv4.h b/include/net/cipso_ipv4.h
index a8c2ef6d3b93..9078b31d336f 100644
--- a/include/net/cipso_ipv4.h
+++ b/include/net/cipso_ipv4.h
@@ -303,6 +303,10 @@ static inline int cipso_v4_validate(const struct sk_buff *skb,
 	}
 
 	for (opt_iter = 6; opt_iter < opt_len;) {
+		if (opt_iter + 1 == opt_len) {
+			err_offset = opt_iter;
+			goto out;
+		}
 		tag_len = opt[opt_iter + 1];
 		if ((tag_len == 0) || (opt[opt_iter + 1] > (opt_len - opt_iter))) {
 			err_offset = opt_iter + 1;
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index dbec8b5a9d8a..a8c5d2c4e345 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1649,6 +1649,10 @@ int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
 				goto validate_return_locked;
 			}
 
+		if (opt_iter + 1 == opt_len) {
+			err_offset = opt_iter;
+			goto validate_return_locked;
+		}
 		tag_len = tag[1];
 		if (tag_len > (opt_len - opt_iter)) {
 			err_offset = opt_iter + 1;