udp: using datalen to cap ipv6 udp max gso segments

BugLink: https://bugs.launchpad.net/bugs/1956926
[ Upstream commit 736ef37fd9a44f5966e25319d08ff7ea99ac79e8 ]

The max number of UDP gso segments is intended to cap to
UDP_MAX_SEGMENTS, this is checked in udp_send_skb().

skb->len contains network and transport header len here, we should use
only data len instead.

This is the ipv6 counterpart to the below referenced commit,
which missed the ipv6 change

Fixes: 158390e45612 ("udp: using datalen to cap max gso segments")
Signed-off-by: Coco Li <lixiaoyan@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20211223222441.2975883-1-lixiaoyan@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <p.pisati@gmail.com>

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 7bee95d8d2df09829a43e5fc63ed13cdd395017c..8cd8c0bce0986ce5ee21aff687f357c8e188e47b 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -1204,7 +1204,7 @@ static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6,
                        kfree_skb(skb);
                        return -EINVAL;
                }
-               if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) {
+               if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) {
                        kfree_skb(skb);
                        return -EINVAL;
                }