From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Fri, 12 Apr 2019 10:53:10 +0000 (+0900)
Subject: sctp: Check address length before reading address family
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=175f7c1f01d30b2088491bee4636fbf846fb76ce;p=openwrt%2Fstaging%2Fblogic.git

sctp: Check address length before reading address family

KMSAN will complain if valid address length passed to connect() is shorter
than sizeof("struct sockaddr"->sa_family) bytes.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 9874e60c9b0d..4583fa914e62 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -4847,7 +4847,8 @@ static int sctp_connect(struct sock *sk, struct sockaddr *addr,
 	}
 
 	/* Validate addr_len before calling common connect/connectx routine. */
-	af = sctp_get_af_specific(addr->sa_family);
+	af = addr_len < offsetofend(struct sockaddr, sa_family) ? NULL :
+		sctp_get_af_specific(addr->sa_family);
 	if (!af || addr_len < af->sockaddr_len) {
 		err = -EINVAL;
 	} else {