Commit bc54d98b authored Jun 23, 2021 by Eric Dumazet Committed by Greg Kroah-Hartman Jul 14, 2021

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: 47d3d7ac ("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>

parent 28db4b5b

net/ipv6/exthdrs.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -305,7 +305,7 @@ static int ipv6_destopt_rcv(struct sk_buff *skb)
		#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)
		@@ -844,7 +844,7 @@ int ipv6_parse_hopopts(struct sk_buff *skb)

		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);