[PATCH 5.4 23/88] udp: using datalen to cap max gso segments

Greg Kroah-Hartman
2021-12-13T09:49:04Z

From: Jianguo Wu <wujianguo@chinatelecom.cn>

commit 158390e45612ef0fde160af0826f1740c36daf21 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: bec1f6f69736 ("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>
---
net/ipv4/udp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -845,7 +845,7 @@ static int udp_send_skb(struct sk_buff *
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;
}