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| author | Jesper Dangaard Brouer <brouer@redhat.com> | 2018-07-11 17:01:20 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-07-12 16:40:19 -0700 |
| commit | 0761680d521559813648fb430ddeb479c97ab060 (patch) | |
| tree | 6bce7e07bdfb49262de929207211745bcff3c00c /net/ipv4/ip_input.c | |
| parent | 51bef926be1e3154996ce400d862aebb98ccbed6 (diff) | |
| download | linux-0761680d521559813648fb430ddeb479c97ab060.tar.gz linux-0761680d521559813648fb430ddeb479c97ab060.tar.bz2 linux-0761680d521559813648fb430ddeb479c97ab060.zip | |
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 'net/ipv4/ip_input.c')
| -rw-r--r-- | net/ipv4/ip_input.c | 8 |
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; dst_input(skb); + } } static void ip_list_rcv_finish(struct net *net, struct sock *sk, |