af_iucv: Move sockaddr length checks to before accessing sa_family in…

… bind 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_IUCV 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. Fixes: 52a82e2 ("af_iucv: Validate socket address length in iucv_sock_bind()") Signed-off-by: Mateusz Jurczyk <[email protected]> [jwi: removed unneeded null-check for addr] Signed-off-by: Julian Wiedmann <[email protected]> Signed-off-by: David S. Miller <[email protected]>
josf · Jun 25, 2017 · e3c42b6 · e3c42b6
1 parent 2e56c26
commit e3c42b6
Showing 1 changed file with 3 additions and 5 deletions.
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
@@ -715,10 +715,8 @@ static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
 	char uid[9];
 
 	/* Verify the input sockaddr */
-	if (!addr || addr->sa_family != AF_IUCV)
-		return -EINVAL;
-
-	if (addr_len < sizeof(struct sockaddr_iucv))
+	if (addr_len < sizeof(struct sockaddr_iucv) ||
+	    addr->sa_family != AF_IUCV)
 		return -EINVAL;
 
 	lock_sock(sk);
@@ -862,7 +860,7 @@ static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
 	struct iucv_sock *iucv = iucv_sk(sk);
 	int err;
 
-	if (addr->sa_family != AF_IUCV || alen < sizeof(struct sockaddr_iucv))
+	if (alen < sizeof(struct sockaddr_iucv) || addr->sa_family != AF_IUCV)
 		return -EINVAL;
 
 	if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)