From 59c3fa2f2f0f6e485d69e6f0115e44ba848079ba Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Tue, 11 Oct 2022 14:27:28 -0700
Subject: [PATCH 1/1] ipv6: ping: fix wrong checksum for large frames
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Git-commit: 87445f369cca2965620e79f87145d3d7fa35befd
Patch-mainline: v6.1-rc1
References: bsc#1203183

For a given ping datagram, ping_getfrag() is called once
per skb fragment.

A large datagram requiring more than one page fragment
is currently getting the checksum of the last fragment,
instead of the cumulative one.

After this patch, "ping -s 35000 ::1" is working correctly.

Fixes: 6d0bfe226116 ("net: ipv6: Add IPv6 support to the ping socket.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Firo Yang <firo.yang@suse.com>
---
 net/ipv4/ping.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 1b6874cacdbe..a9ca98214f1e 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -628,7 +628,7 @@ int ping_getfrag(void *from, char *to,
 	 * wcheck, it will be finalized in ping_v4_push_pending_frames.
 	 */
 	if (pfh->family == AF_INET6) {
-		skb->csum = pfh->wcheck;
+		skb->csum = csum_block_add(skb->csum, pfh->wcheck, odd);
 		skb->ip_summed = CHECKSUM_NONE;
 		pfh->wcheck = 0;
 	}
-- 
2.26.2