af_unix: Add sockaddr length checks before accessing sa_family in bin…

…d and connect handlers Verify that the caller-provided sockaddr structure is large enough to contain the sa_family field, before accessing it in bind() and connect() handlers of the AF_UNIX socket. Since neither syscall enforces a minimum size of the corresponding memory region, very short sockaddrs (zero or one byte long) result in operating on uninitialized memory while referencing .sa_family. Signed-off-by: Mateusz Jurczyk <[email protected]> Signed-off-by: David S. Miller <[email protected]>
josf · Jun 9, 2017 · defbcf2 · defbcf2
1 parent fc5b775
commit defbcf2
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
@@ -999,7 +999,8 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	struct path path = { };
 
 	err = -EINVAL;
-	if (sunaddr->sun_family != AF_UNIX)
+	if (addr_len < offsetofend(struct sockaddr_un, sun_family) ||
+	    sunaddr->sun_family != AF_UNIX)
 		goto out;
 
 	if (addr_len == sizeof(short)) {
@@ -1110,6 +1111,10 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
 	unsigned int hash;
 	int err;
 
+	err = -EINVAL;
+	if (alen < offsetofend(struct sockaddr, sa_family))
+		goto out;
+
 	if (addr->sa_family != AF_UNSPEC) {
 		err = unix_mkname(sunaddr, alen, &hash);
 		if (err < 0)