netdev - [PATCH net-next v2 3/3] net/sched: act_ct: fix clobber qdisc_skb

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

Date:   Tue,  7 Jul 2020 12:55:11 +0800
From:   wenxu@...oud.cn
To:     netdev@...r.kernel.org
Cc:     netfilter-devel@...r.kernel.org, fw@...len.de
Subject: [PATCH net-next v2 3/3] net/sched: act_ct: fix clobber qdisc_skb_cb in defrag

From: wenxu <wenxu@...oud.cn>

using ip_defrag_ignore_cb to defrag in act_ct to elide CB clear.
Avoid serious crashes and problems in ct subsystem. Because Some packet
schedulers store pointers in the qdisc CB private area and Parallel
accesses to the SKB.

Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")
Signed-off-by: wenxu <wenxu@...oud.cn>
---
 net/sched/act_ct.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
index 20f3d11..a8e9e62 100644
--- a/net/sched/act_ct.c
+++ b/net/sched/act_ct.c
@@ -697,10 +697,7 @@ static int tcf_ct_handle_fragments(struct net *net, struct sk_buff *skb,
 	if (family == NFPROTO_IPV4) {
 		enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
 
-		memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
-		local_bh_disable();
-		err = ip_defrag(net, skb, user);
-		local_bh_enable();
+		err = ip_defrag_ignore_cb(net, skb, user, NULL);
 		if (err && err != -EINPROGRESS)
 			goto out_free;
 	} else { /* NFPROTO_IPV6 */
-- 
1.8.3.1