Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index ef5560b..ba86195 100644
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -688,6 +688,9 @@
 	if (!cdev->ap.applid)
 		return -ENODEV;
 
+	if (count < CAPIMSG_BASELEN)
+		return -EINVAL;
+
 	skb = alloc_skb(count, GFP_USER);
 	if (!skb)
 		return -ENOMEM;
@@ -698,7 +701,8 @@
 	}
 	mlen = CAPIMSG_LEN(skb->data);
 	if (CAPIMSG_CMD(skb->data) == CAPI_DATA_B3_REQ) {
-		if ((size_t)(mlen + CAPIMSG_DATALEN(skb->data)) != count) {
+		if (count < CAPI_DATA_B3_REQ_LEN ||
+		    (size_t)(mlen + CAPIMSG_DATALEN(skb->data)) != count) {
 			kfree_skb(skb);
 			return -EINVAL;
 		}
@@ -711,6 +715,10 @@
 	CAPIMSG_SETAPPID(skb->data, cdev->ap.applid);
 
 	if (CAPIMSG_CMD(skb->data) == CAPI_DISCONNECT_B3_RESP) {
+		if (count < CAPI_DISCONNECT_B3_RESP_LEN) {
+			kfree_skb(skb);
+			return -EINVAL;
+		}
 		mutex_lock(&cdev->lock);
 		capincci_free(cdev, CAPIMSG_NCCI(skb->data));
 		mutex_unlock(&cdev->lock);
@@ -736,7 +744,7 @@
 
 	poll_wait(file, &(cdev->recvwait), wait);
 	mask = EPOLLOUT | EPOLLWRNORM;
-	if (!skb_queue_empty(&cdev->recvqueue))
+	if (!skb_queue_empty_lockless(&cdev->recvqueue))
 		mask |= EPOLLIN | EPOLLRDNORM;
 	return mask;
 }
@@ -960,7 +968,7 @@
 	list_add_tail(&cdev->list, &capidev_list);
 	mutex_unlock(&capidev_list_lock);
 
-	return nonseekable_open(inode, file);
+	return stream_open(inode, file);
 }
 
 static int capi_release(struct inode *inode, struct file *file)
@@ -1155,12 +1163,6 @@
 	return mp->outbytes;
 }
 
-static int capinc_tty_ioctl(struct tty_struct *tty,
-			    unsigned int cmd, unsigned long arg)
-{
-	return -ENOIOCTLCMD;
-}
-
 static void capinc_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 {
 	pr_debug("capinc_tty_set_termios\n");
@@ -1236,7 +1238,6 @@
 	.flush_chars = capinc_tty_flush_chars,
 	.write_room = capinc_tty_write_room,
 	.chars_in_buffer = capinc_tty_chars_in_buffer,
-	.ioctl = capinc_tty_ioctl,
 	.set_termios = capinc_tty_set_termios,
 	.throttle = capinc_tty_throttle,
 	.unthrottle = capinc_tty_unthrottle,