From: Eric Dumazet <edumazet@google.com>
Date: Wed, 23 Jun 2021 15:27:00 +0000 (-0700)
Subject: ipv6: exthdrs: do not blindly use init_net
X-Git-Tag: v5.12.17~229
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bd5046d72d9096c98a3d1f71e5abef7832a4d8cf;p=thirdparty%2Fkernel%2Fstable.git

ipv6: exthdrs: do not blindly use init_net

[ Upstream commit bcc3f2a829b9edbe3da5fb117ee5a63686d31834 ]

I see no reason why max_dst_opts_cnt and max_hbh_opts_cnt
are fetched from the initial net namespace.

The other sysctls (max_dst_opts_len & max_hbh_opts_len)
are in fact already using the current ns.

Note: it is not clear why ipv6_destopt_rcv() use two ways to
get to the netns :

 1) dev_net(dst->dev)
    Originally used to increment IPSTATS_MIB_INHDRERRORS

 2) dev_net(skb->dev)
     Tom used this variant in his patch.

Maybe this calls to use ipv6_skb_net() instead ?

Fixes: 47d3d7ac656a ("ipv6: Implement limits on Hop-by-Hop and Destination options")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@quantonium.net>
Cc: Coco Li <lixiaoyan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 6126f8bf94b39..a9e1d7918d142 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -306,7 +306,7 @@ fail_and_free:
 #endif
 
 	if (ip6_parse_tlv(tlvprocdestopt_lst, skb,
-			  init_net.ipv6.sysctl.max_dst_opts_cnt)) {
+			  net->ipv6.sysctl.max_dst_opts_cnt)) {
 		skb->transport_header += extlen;
 		opt = IP6CB(skb);
 #if IS_ENABLED(CONFIG_IPV6_MIP6)
@@ -1036,7 +1036,7 @@ fail_and_free:
 
 	opt->flags |= IP6SKB_HOPBYHOP;
 	if (ip6_parse_tlv(tlvprochopopt_lst, skb,
-			  init_net.ipv6.sysctl.max_hbh_opts_cnt)) {
+			  net->ipv6.sysctl.max_hbh_opts_cnt)) {
 		skb->transport_header += extlen;
 		opt = IP6CB(skb);
 		opt->nhoff = sizeof(struct ipv6hdr);