caif: Add sockaddr length check before accessing sa_family in connect handler

Verify that the caller-provided sockaddr structure is large enough to
contain the sa_family field, before accessing it in the connect()
handler of the AF_CAIF socket. Since the syscall doesn't enforce 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 <mjurczyk@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
index adcad344c843..21f18ea2fce4 100644
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -754,6 +754,10 @@ static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
 
         lock_sock(sk);
 
+        err = -EINVAL;
+        if (addr_len < offsetofend(struct sockaddr, sa_family))
+                goto out;
+
         err = -EAFNOSUPPORT;
         if (uaddr->sa_family != AF_CAIF)
                 goto out;