This is a note to let you know that I've just added the patch titled
ipv6: Do not leak throw route references
to the 4.4-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:
ipv6-do-not-leak-throw-route-references.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Jun 29 19:38:17 CEST 2017
From: Serhey Popovych <serhe.popovych@xxxxxxxxx>
Date: Tue, 20 Jun 2017 13:29:25 +0300
Subject: ipv6: Do not leak throw route references
From: Serhey Popovych <serhe.popovych@xxxxxxxxx>
[ Upstream commit 07f615574f8ac499875b21c1142f26308234a92c ]
While commit 73ba57bfae4a ("ipv6: fix backtracking for throw routes")
does good job on error propagation to the fib_rules_lookup()
in fib rules core framework that also corrects throw routes
handling, it does not solve route reference leakage problem
happened when we return -EAGAIN to the fib_rules_lookup()
and leave routing table entry referenced in arg->result.
If rule with matched throw route isn't last matched in the
list we overwrite arg->result losing reference on throw
route stored previously forever.
We also partially revert commit ab997ad40839 ("ipv6: fix the
incorrect return value of throw route") since we never return
routing table entry with dst.error == -EAGAIN when
CONFIG_IPV6_MULTIPLE_TABLES is on. Also there is no point
to check for RTF_REJECT flag since it is always set throw
route.
Fixes: 73ba57bfae4a ("ipv6: fix backtracking for throw routes")
Signed-off-by: Serhey Popovych <serhe.popovych@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/fib6_rules.c | 22 ++++++----------------
net/ipv6/ip6_fib.c | 3 +--
2 files changed, 7 insertions(+), 18 deletions(-)
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -32,7 +32,6 @@ struct fib6_rule {
struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
int flags, pol_lookup_t lookup)
{
- struct rt6_info *rt;
struct fib_lookup_arg arg = {
.lookup_ptr = lookup,
.flags = FIB_LOOKUP_NOREF,
@@ -41,21 +40,11 @@ struct dst_entry *fib6_rule_lookup(struc
fib_rules_lookup(net->ipv6.fib6_rules_ops,
flowi6_to_flowi(fl6), flags, &arg);
- rt = arg.result;
+ if (arg.result)
+ return arg.result;
- if (!rt) {
- dst_hold(&net->ipv6.ip6_null_entry->dst);
- return &net->ipv6.ip6_null_entry->dst;
- }
-
- if (rt->rt6i_flags & RTF_REJECT &&
- rt->dst.error == -EAGAIN) {
- ip6_rt_put(rt);
- rt = net->ipv6.ip6_null_entry;
- dst_hold(&rt->dst);
- }
-
- return &rt->dst;
+ dst_hold(&net->ipv6.ip6_null_entry->dst);
+ return &net->ipv6.ip6_null_entry->dst;
}
static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
@@ -116,7 +105,8 @@ static int fib6_rule_action(struct fib_r
flp6->saddr = saddr;
}
err = rt->dst.error;
- goto out;
+ if (err != -EAGAIN)
+ goto out;
}
again:
ip6_rt_put(rt);
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -290,8 +290,7 @@ struct dst_entry *fib6_rule_lookup(struc
struct rt6_info *rt;
rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, flags);
- if (rt->rt6i_flags & RTF_REJECT &&
- rt->dst.error == -EAGAIN) {
+ if (rt->dst.error == -EAGAIN) {
ip6_rt_put(rt);
rt = net->ipv6.ip6_null_entry;
dst_hold(&rt->dst);
Patches currently in stable-queue which might be from serhe.popovych@xxxxxxxxx are
queue-4.4/rtnetlink-add-ifla_group-to-ifla_policy.patch
queue-4.4/ipv6-do-not-leak-throw-route-references.patch