can: add sanity checks

[pandora-kernel.git] / net / can / bcm.c

diff --git a/net/can/bcm.c b/net/can/bcm.c
index d9a3a9d..72c2ce9 100644 (file)
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -298,7 +298,7 @@ static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
 
        if (head->nframes) {
                /* can_frames starting here */
-               firstframe = (struct can_frame *) skb_tail_pointer(skb);
+               firstframe = (struct can_frame *)skb_tail_pointer(skb);
 
                memcpy(skb_put(skb, datalen), frames, datalen);
 
@@ -826,6 +826,10 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
                for (i = 0; i < msg_head->nframes; i++) {
                        err = memcpy_fromiovec((u8 *)&op->frames[i],
                                               msg->msg_iov, CFSIZ);
+
+                       if (op->frames[i].can_dlc > 8)
+                               err = -EINVAL;
+
                        if (err < 0)
                                return err;
 
@@ -858,6 +862,10 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
                for (i = 0; i < msg_head->nframes; i++) {
                        err = memcpy_fromiovec((u8 *)&op->frames[i],
                                               msg->msg_iov, CFSIZ);
+
+                       if (op->frames[i].can_dlc > 8)
+                               err = -EINVAL;
+
                        if (err < 0) {
                                if (op->frames != &op->sframe)
                                        kfree(op->frames);
@@ -1164,9 +1172,12 @@ static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
 
        skb->dev = dev;
        skb->sk  = sk;
-       can_send(skb, 1); /* send with loopback */
+       err = can_send(skb, 1); /* send with loopback */
        dev_put(dev);
 
+       if (err)
+               return err;
+
        return CFSIZ + MHSIZ;
 }
 
@@ -1185,6 +1196,10 @@ static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
        if (!bo->bound)
                return -ENOTCONN;
 
+       /* check for valid message length from userspace */
+       if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
+               return -EINVAL;
+
        /* check for alternative ifindex for this bcm_op */
 
        if (!ifindex && msg->msg_name) {
@@ -1259,8 +1274,8 @@ static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
                break;
 
        case TX_SEND:
-               /* we need at least one can_frame */
-               if (msg_head.nframes < 1)
+               /* we need exactly one can_frame behind the msg head */
+               if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
                        ret = -EINVAL;
                else
                        ret = bcm_tx_send(msg, ifindex, sk);