crypto: msm: restrict value of num_fds to QCEDEV_MAX_BUFFERS

Set the max value of num_fds to QCEDEV_MAX_BUFFERS to prevent
out of bound access of fd, fd_size, fd_offset array.

Change-Id: I88889472a4bd14f786588bd2c9e06e69a98e94c9
Signed-off-by: Prerna Kalla <prernak@codeaurora.org>

drivers/crypto/msm/qcedev.c

@@ -1915,6 +1915,11 @@ static inline long qcedev_ioctl(struct file *file,
 				goto exit_free_qcedev_areq;
 			}
 
+			if (map_buf.num_fds > QCEDEV_MAX_BUFFERS) {
+				err = -EINVAL;
+				goto exit_free_qcedev_areq;
+			}
+
 			for (i = 0; i < map_buf.num_fds; i++) {
 				err = qcedev_check_and_map_buffer(handle,
 						map_buf.fd[i],