diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 6e70839257f7..91715603cf6e 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1158,10 +1158,15 @@ static int __ip_append_data(struct sock *sk,
 			}
 
 			copy = datalen - transhdrlen - fraggap - pagedlen;
+			/* [!] NOTE: copy will be negative if pagedlen>0
+			 * because then the equation reduces to -fraggap.
+			 */
 			if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
 				err = -EFAULT;
 				kfree_skb(skb);
 				goto error;
+			} else if (flags & MSG_SPLICE_PAGES) {
+				copy = 0;
 			}
 
 			offset += copy;
@@ -1209,6 +1214,10 @@ static int __ip_append_data(struct sock *sk,
 		} else if (flags & MSG_SPLICE_PAGES) {
 			struct msghdr *msg = from;
 
+			err = -EIO;
+			if (WARN_ON_ONCE(copy > msg->msg_iter.count))
+				goto error;
+
 			err = skb_splice_from_iter(skb, &msg->msg_iter, copy,
 						   sk->sk_allocation);
 			if (err < 0)