path: root/net/ipv4/ip_input.c
diff options
authorJesper Dangaard Brouer <brouer@redhat.com>2018-07-11 17:01:20 +0200
committerDavid S. Miller <davem@davemloft.net>2018-07-12 16:40:19 -0700
commit0761680d521559813648fb430ddeb479c97ab060 (patch)
tree6bce7e07bdfb49262de929207211745bcff3c00c /net/ipv4/ip_input.c
parentnfp: avoid using getnstimeofday64() (diff)
net: ipv4: fix listify ip_rcv_finish in case of forwarding
In commit 5fa12739a53d ("net: ipv4: listify ip_rcv_finish") calling dst_input(skb) was split-out. The ip_sublist_rcv_finish() just calls dst_input(skb) in a loop. The problem is that ip_sublist_rcv_finish() forgot to remove the SKB from the list before invoking dst_input(). Further more we need to clear skb->next as other parts of the network stack use another kind of SKB lists for xmit_more (see dev_hard_start_xmit). A crash occurs if e.g. dst_input() invoke ip_forward(), which calls dst_output()/ip_output() that eventually calls __dev_queue_xmit() + sch_direct_xmit(), and a crash occurs in validate_xmit_skb_list(). This patch only fixes the crash, but there is a huge potential for a performance boost if we can pass an SKB-list through to ip_forward. Fixes: 5fa12739a53d ("net: ipv4: listify ip_rcv_finish") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Edward Cree <ecree@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
1 files changed, 7 insertions, 1 deletions
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 1a3b6f32b1c9..3196cf58f418 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -530,8 +530,14 @@ static void ip_sublist_rcv_finish(struct list_head *head)
struct sk_buff *skb, *next;
- list_for_each_entry_safe(skb, next, head, list)
+ list_for_each_entry_safe(skb, next, head, list) {
+ list_del(&skb->list);
+ /* Handle ip{6}_forward case, as sch_direct_xmit have
+ * another kind of SKB-list usage (see validate_xmit_skb_list)
+ */
+ skb->next = NULL;
+ }
static void ip_list_rcv_finish(struct net *net, struct sock *sk,