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Patch "net: sched: set xt_tgchk_param par.net properly in ipt_init_target" has been added to the 4.12-stable tree

PATCH [email protected] 1 participant 1 message Aug 11, 2017

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This is a note to let you know that I've just added the patch titled

net: sched: set xt_tgchk_param par.net properly in ipt_init_target

to the 4.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
net-sched-set-xt_tgchk_param-par.net-properly-in-ipt_init_target.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From foo@baz Fri Aug 11 09:09:38 PDT 2017

From: Xin Long <[email protected]>
Date: Tue, 8 Aug 2017 15:25:25 +0800
Subject: net: sched: set xt_tgchk_param par.net properly in ipt_init_target

From: Xin Long <[email protected]>

[ Upstream commit ec0acb09313074ba1a4976945791d9c6815f39fb ]

Now xt_tgchk_param par in ipt_init_target is a local varibale, par.net is not initialized there. Later when xt_check_target calls target's checkentry in which it may access par.net, it would cause kernel panic.

Jaroslav found this panic when running:

  # ip link add TestIface type dummy
  # tc qd add dev TestIface ingress handle ffff:
  # tc filter add dev TestIface parent ffff: u32 match u32 0 0 \
    action xt -j CONNMARK --set-mark 4

This patch is to pass net param into ipt_init_target and set par.net with it properly in there.

v1->v2:
As Wang Cong pointed, I missed ipt_net_id != xt_net_id, so fix it by also passing net_id to __tcf_ipt_init.
v2->v3:
Missed the fixes tag, so add it.

Fixes ecb2421b5ddf ("netfilter: add and use nf_ct_netns_get/put")
Reported-by Jaroslav Aster <[email protected]>
Signed-off-by Xin Long <[email protected]>
Acked-by Jiri Pirko <[email protected]>
Signed-off-by David S. Miller <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 net/sched/act_ipt.c |   20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)
net/sched/act_ipt.c +10 -10
@@ -36,8 +36,8 @@ static struct tc_action_ops act_ipt_ops;
 static unsigned int xt_net_id;
 static struct tc_action_ops act_xt_ops;
 
-static int ipt_init_target(struct xt_entry_target *t, char *table,
-			   unsigned int hook)
+static int ipt_init_target(struct net *net, struct xt_entry_target *t,
+			   char *table, unsigned int hook)
 {
 	struct xt_tgchk_param par;
 	struct xt_target *target;

@@ -49,6 +49,7 @@ static int ipt_init_target(struct xt_ent
 		return PTR_ERR(target);
 
 	t->u.kernel.target = target;
+	par.net       = net;
 	par.table     = table;
 	par.entryinfo = NULL;
 	par.target    = target;

@@ -91,10 +92,11 @@ static const struct nla_policy ipt_polic
 	[TCA_IPT_TARG]	= { .len = sizeof(struct xt_entry_target) },
 };
 
-static int __tcf_ipt_init(struct tc_action_net *tn, struct nlattr *nla,
+static int __tcf_ipt_init(struct net *net, unsigned int id, struct nlattr *nla,
 			  struct nlattr *est, struct tc_action **a,
 			  const struct tc_action_ops *ops, int ovr, int bind)
 {
+	struct tc_action_net *tn = net_generic(net, id);
 	struct nlattr *tb[TCA_IPT_MAX + 1];
 	struct tcf_ipt *ipt;
 	struct xt_entry_target *td, *t;

@@ -159,7 +161,7 @@ static int __tcf_ipt_init(struct tc_acti
 	if (unlikely(!t))
 		goto err2;
 
-	err = ipt_init_target(t, tname, hook);
+	err = ipt_init_target(net, t, tname, hook);
 	if (err < 0)
 		goto err3;
 

@@ -193,18 +195,16 @@ static int tcf_ipt_init(struct net *net,
 			struct nlattr *est, struct tc_action **a, int ovr,
 			int bind)
 {
-	struct tc_action_net *tn = net_generic(net, ipt_net_id);
-
-	return __tcf_ipt_init(tn, nla, est, a, &act_ipt_ops, ovr, bind);
+	return __tcf_ipt_init(net, ipt_net_id, nla, est, a, &act_ipt_ops, ovr,
+			      bind);
 }
 
 static int tcf_xt_init(struct net *net, struct nlattr *nla,
 		       struct nlattr *est, struct tc_action **a, int ovr,
 		       int bind)
 {
-	struct tc_action_net *tn = net_generic(net, xt_net_id);
-
-	return __tcf_ipt_init(tn, nla, est, a, &act_xt_ops, ovr, bind);
+	return __tcf_ipt_init(net, xt_net_id, nla, est, a, &act_xt_ops, ovr,
+			      bind);
 }
 
 static int tcf_ipt(struct sk_buff *skb, const struct tc_action *a,

Patches currently in stable-queue which might be from [email protected] are

queue-4.12/ipv6-set-rt6i_protocol-properly-in-the-route-when-it-is-installed.patch queue-4.12/net-sched-set-xt_tgchk_param-par.nft_compat-as-0-in-ipt_init_target.patch queue-4.12/net-sched-set-xt_tgchk_param-par.net-properly-in-ipt_init_target.patch