net: core: fix use-after-free in __netif_receive_skb_list_core
__netif_receive_skb_core can free the skb, so we have to use the dequeue-
enqueue model when calling it from __netif_receive_skb_list_core.
Fixes: 88eb1944e18c ("net: core: propagate SKB lists through packet_type lookup")
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index ce45835..d13cddc 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4830,23 +4830,28 @@ static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemallo
struct list_head sublist;
struct sk_buff *skb, *next;
+ INIT_LIST_HEAD(&sublist);
list_for_each_entry_safe(skb, next, head, list) {
struct net_device *orig_dev = skb->dev;
struct packet_type *pt_prev = NULL;
+ list_del(&skb->list);
__netif_receive_skb_core(skb, pfmemalloc, &pt_prev);
+ if (!pt_prev)
+ continue;
if (pt_curr != pt_prev || od_curr != orig_dev) {
/* dispatch old sublist */
- list_cut_before(&sublist, head, &skb->list);
__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
/* start new sublist */
+ INIT_LIST_HEAD(&sublist);
pt_curr = pt_prev;
od_curr = orig_dev;
}
+ list_add_tail(&skb->list, &sublist);
}
/* dispatch final sublist */
- __netif_receive_skb_list_ptype(head, pt_curr, od_curr);
+ __netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
}
static int __netif_receive_skb(struct sk_buff *skb)