Bluetooth: Add sockaddr length checks 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 Bluetooth sockets. 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 <mjurczyk@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 507b80d59dec..67a8642f57ea 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -87,7 +87,8 @@ static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
 
         BT_DBG("sk %p", sk);
 
-        if (!addr || addr->sa_family != AF_BLUETOOTH)
+        if (!addr || alen < offsetofend(struct sockaddr, sa_family) ||
+            addr->sa_family != AF_BLUETOOTH)
                 return -EINVAL;
 
         memset(&la, 0, sizeof(la));
@@ -181,7 +182,7 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr,
 
         BT_DBG("sk %p", sk);
 
-        if (!addr || alen < sizeof(addr->sa_family) ||
+        if (!addr || alen < offsetofend(struct sockaddr, sa_family) ||
             addr->sa_family != AF_BLUETOOTH)
                 return -EINVAL;