[PATCH 3/3] tomoyo: Check address length before reading address family

From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: linux-security-module@vger.kernel.org
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Subject: [PATCH 3/3] tomoyo: Check address length before reading address family
Date: Fri, 12 Apr 2019 19:59:36 +0900	[thread overview]
Message-ID: <1555066776-9758-3-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <1555066776-9758-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp>

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

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
 security/tomoyo/network.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/security/tomoyo/network.c b/security/tomoyo/network.c
index 9094f4b3b367..f9ff121d7e1e 100644
--- a/security/tomoyo/network.c
+++ b/security/tomoyo/network.c
@@ -505,6 +505,8 @@ static int tomoyo_check_inet_address(const struct sockaddr *addr,
 {
 	struct tomoyo_inet_addr_info *i = &address->inet;
 
+	if (addr_len < offsetofend(struct sockaddr, sa_family))
+		return 0;
 	switch (addr->sa_family) {
 	case AF_INET6:
 		if (addr_len < SIN6_LEN_RFC2133)
@@ -594,6 +596,8 @@ static int tomoyo_check_unix_address(struct sockaddr *addr,
 {
 	struct tomoyo_unix_addr_info *u = &address->unix0;
 
+	if (addr_len < offsetofend(struct sockaddr, sa_family))
+		return 0;
 	if (addr->sa_family != AF_UNIX)
 		return 0;
 	u->addr = ((struct sockaddr_un *) addr)->sun_path;
-- 
2.16.5

