udp: using datalen to cap max gso segments

stable inclusion
from stable-v5.10.85
commit 5e39de85b76ec52fc396a036efacea919aa102e7
bugzilla: 186032 https://gitee.com/openeuler/kernel/issues/I4QVI4

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5e39de85b76ec52fc396a036efacea919aa102e7



--------------------------------

commit 158390e4 upstream.

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

    if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) {
        kfree_skb(skb);
        return -EINVAL;
    }

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

Fixes: bec1f6f6 ("udp: generate gso with UDP_SEGMENT")
Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/900742e5-81fb-30dc-6e0b-375c6cdd7982@163.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>