Re: Question about inet_rtm_getroute_build_skb()
From: David Ahern <hidden>
Date: 2021-08-27 04:37:18
On 8/26/21 6:16 PM, Eric Dumazet wrote:
Hi Roopa I noticed inet_rtm_getroute_build_skb() has this endian issue when building an UDP header. Would the following fix break user space ?
I do not see how. As I recall this is only for going through ip_route_input_rcu and ip_route_output_key_hash_rcu and a call to fib4_rules_early_flow_dissect.
quoted hunk ↗ jump to hunk
Thanks.diff --git a/net/ipv4/route.c b/net/ipv4/route.c index a6f20ee3533554b210d27c4ab6637ca7a05b148b..50133b935f868c2ae9474eea027a0ad864a43936 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c@@ -3170,7 +3170,7 @@ static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, udph = skb_put_zero(skb, sizeof(struct udphdr)); udph->source = sport; udph->dest = dport; - udph->len = sizeof(struct udphdr); + udph->len = htons(sizeof(struct udphdr)); udph->check = 0; break; }