On Fri, 2014-01-31 at 22:11 +0200, Tommi Rantala wrote:
> Hello,
>
> Hit this while fuzzing v3.13-9218-g0e47c96 with trinity in a qemu
> virtual machine.
>
> Tommi
Hi Tommi
Could you please try the following fix ?
I'll send an official patch in a couple of hours
There are two bugs :
One dst leak, and one plain bug, as rt initial NULL
value might be scratched.
net/ipv4/ip_tunnel.c | 27 ++++++++++-----------------
1 file changed, 10 insertions(+), 17 deletions(-)
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index bd28f386bd02..bc6acdcb7625 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -101,27 +101,21 @@ static void tunnel_dst_reset_all(struct ip_tunnel *t)
__tunnel_dst_set(per_cpu_ptr(t->dst_cache, i), NULL);
}
-static struct dst_entry *tunnel_dst_get(struct ip_tunnel *t)
+static struct dst_entry *tunnel_dst_check(struct ip_tunnel *t, u32 cookie)
{
struct dst_entry *dst;
rcu_read_lock();
dst = rcu_dereference(this_cpu_ptr(t->dst_cache)->dst);
- if (dst)
+ if (dst) {
+ if (dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
+ rcu_read_unlock();
+ tunnel_dst_reset(t);
+ return NULL;
+ }
dst_hold(dst);
- rcu_read_unlock();
- return dst;
-}
-
-static struct dst_entry *tunnel_dst_check(struct ip_tunnel *t, u32 cookie)
-{
- struct dst_entry *dst = tunnel_dst_get(t);
-
- if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
- tunnel_dst_reset(t);
- return NULL;
}
-
+ rcu_read_unlock();
return dst;
}
@@ -584,7 +578,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device
*dev,
struct flowi4 fl4;
u8 tos, ttl;
__be16 df;
- struct rtable *rt = NULL; /* Route to the other host */
+ struct rtable *rt; /* Route to the other host */
unsigned int max_headroom; /* The extra header space needed */
__be32 dst;
int err;
@@ -657,8 +651,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device
*dev,
init_tunnel_flow(&fl4, protocol, dst, tnl_params->saddr,
tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link);
- if (connected)
- rt = (struct rtable *)tunnel_dst_check(tunnel, 0);
+ rt = (connected) ? (struct rtable *)tunnel_dst_check(tunnel, 0) : NULL;
if (!rt) {
rt = ip_route_output_key(tunnel->net, &fl4);
--
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