kernel: socket: Ensure AF_UNIX in recvmsg()mainexpt

Ensure that the file descriptor represented by 'socket' is of type
AF_UNIX before performing the rest of recvmsg()

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/sys/kern/kern_socket.c b/sys/kern/kern_socket.c
index 9b98ccc..8be5031 100644
--- a/sys/kern/kern_socket.c
+++ b/sys/kern/kern_socket.c
@@ -403,6 +403,7 @@ ssize_t
 recvmsg(int socket, struct msghdr *msg, int flags)
 {
     struct ksocket *ksock;
+    struct sockaddr_un *un;
     struct cmsg *cmsg, *tmp;
     struct cmsghdr *cmsghdr;
     struct cmsg_list *clp;
@@ -418,6 +419,12 @@ recvmsg(int socket, struct msghdr *msg, int flags)
         return error;
     }
 
+    /* Must be a unix domain socket */
+    un = &ksock->un;
+    if (un->sun_family != AF_UNIX) {
+        return -EBADF;
+    }
+
     /* Grab the control message list */
     clp = &ksock->cmsg_list;
     cmsg = TAILQ_FIRST(&clp->list);