netdev - [PATCHv2 net] ipvs: Always clear ipvs_property flag in skb_scrub

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <20250222033518.126087-1-lulie@linux.alibaba.com>
Date: Sat, 22 Feb 2025 11:35:18 +0800
From: Philo Lu <lulie@...ux.alibaba.com>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net,
	edumazet@...gle.com,
	kuba@...nel.org,
	pabeni@...hat.com,
	horms@...nel.org,
	asml.silence@...il.com,
	willemb@...gle.com,
	almasrymina@...gle.com,
	chopps@...n.net,
	aleksander.lobakin@...el.com,
	nicolas.dichtel@...nd.com,
	dust.li@...ux.alibaba.com,
	hustcat@...il.com,
	ja@....bg,
	horms@...ge.net.au,
	bpf@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCHv2 net] ipvs: Always clear ipvs_property flag in skb_scrub_packet()

We found an issue when using bpf_redirect with ipvs NAT mode after
commit ff70202b2d1a ("dev_forward_skb: do not scrub skb mark within
the same name space"). Particularly, we use bpf_redirect to return
the skb directly back to the netif it comes from, i.e., xnet is
false in skb_scrub_packet(), and then ipvs_property is preserved
and SNAT is skipped in the rx path.

ipvs_property has been already cleared when netns is changed in
commit 2b5ec1a5f973 ("netfilter/ipvs: clear ipvs_property flag when
SKB net namespace changed"). This patch just clears it in spite of
netns.

Fixes: 2b5ec1a5f973 ("netfilter/ipvs: clear ipvs_property flag when SKB net namespace changed")
Signed-off-by: Philo Lu <lulie@...ux.alibaba.com>
---
v1 -> v2:
 - Add Fixes tag as suggested by Julian Anastasov
---
 net/core/skbuff.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 7b03b64fdcb2..b1c81687e9d8 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -6033,11 +6033,11 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet)
 	skb->offload_fwd_mark = 0;
 	skb->offload_l3_fwd_mark = 0;
 #endif
+	ipvs_reset(skb);
 
 	if (!xnet)
 		return;
 
-	ipvs_reset(skb);
 	skb->mark = 0;
 	skb_clear_tstamp(skb);
 }
-- 
2.32.0.3.g01195cf9f