[PATCH 3.18 008/145] netlabel: out of bound access in cipso_v4_validate()

Greg Kroah-Hartman
2017-04-16T10:53:02Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit d71b7896886345c53ef1d84bda2bc758554f5d61 ]

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/net/cipso_ipv4.h | 4 ++++
net/ipv4/cipso_ipv4.c | 4 ++++
2 files changed, 8 insertions(+)

--- a/include/net/cipso_ipv4.h
+++ b/include/net/cipso_ipv4.h
@@ -309,6 +309,10 @@ static inline int cipso_v4_validate(cons
}

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) || (tag_len > (opt_len - opt_iter))) {
err_offset = opt_iter + 1;
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1655,6 +1655,10 @@ int cipso_v4_validate(const struct sk_bu
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;