[NETFILTER]: Fix rcu race in ipt_REDIRECT
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/netfilter/ipt_REDIRECT.c b/net/ipv4/netfilter/ipt_REDIRECT.c
index d2e1344..715cb61 100644
--- a/net/ipv4/netfilter/ipt_REDIRECT.c
+++ b/net/ipv4/netfilter/ipt_REDIRECT.c
@@ -88,14 +88,18 @@
newdst = htonl(0x7F000001);
else {
struct in_device *indev;
+ struct in_ifaddr *ifa;
- /* Device might not have an associated in_device. */
- indev = (struct in_device *)(*pskb)->dev->ip_ptr;
- if (indev == NULL || indev->ifa_list == NULL)
+ newdst = 0;
+
+ rcu_read_lock();
+ indev = __in_dev_get((*pskb)->dev);
+ if (indev && (ifa = indev->ifa_list))
+ newdst = ifa->ifa_local;
+ rcu_read_unlock();
+
+ if (!newdst)
return NF_DROP;
-
- /* Grab first address on interface. */
- newdst = indev->ifa_list->ifa_local;
}
/* Transfer from original range. */