blob: 900cbf9b220b0ce0ae6fff71fca6cb93866af280 [file] [log] [blame]
From b037dbca39d66ced8642baafde7974c3e9a84e8c Mon Sep 17 00:00:00 2001
From: Mahesh Bandewar <maheshb@google.com>
Date: Mon, 9 Mar 2020 15:56:56 -0700
Subject: [PATCH] ipvlan: don't deref eth hdr before checking it's set
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
commit ad8192767c9f9cf97da57b9ffcea70fb100febef upstream.
IPvlan in L3 mode discards outbound multicast packets but performs
the check before ensuring the ether-header is set or not. This is
an error that Eric found through code browsing.
Fixes: 2ad7bf363841 (“ipvlan: Initial check-in of the IPVLAN driver.”)
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c
index 57617ff5565f..8801d093135c 100644
--- a/drivers/net/ipvlan/ipvlan_core.c
+++ b/drivers/net/ipvlan/ipvlan_core.c
@@ -499,19 +499,21 @@ static int ipvlan_process_outbound(struct sk_buff *skb)
struct ethhdr *ethh = eth_hdr(skb);
int ret = NET_XMIT_DROP;
- /* In this mode we dont care about multicast and broadcast traffic */
- if (is_multicast_ether_addr(ethh->h_dest)) {
- pr_debug_ratelimited("Dropped {multi|broad}cast of type=[%x]\n",
- ntohs(skb->protocol));
- kfree_skb(skb);
- goto out;
- }
-
/* The ipvlan is a pseudo-L2 device, so the packets that we receive
* will have L2; which need to discarded and processed further
* in the net-ns of the main-device.
*/
if (skb_mac_header_was_set(skb)) {
+ /* In this mode we dont care about
+ * multicast and broadcast traffic */
+ if (is_multicast_ether_addr(ethh->h_dest)) {
+ pr_debug_ratelimited(
+ "Dropped {multi|broad}cast of type=[%x]\n",
+ ntohs(skb->protocol));
+ kfree_skb(skb);
+ goto out;
+ }
+
skb_pull(skb, sizeof(*ethh));
skb->mac_header = (typeof(skb->mac_header))~0U;
skb_reset_network_header(skb);
--
2.7.4