* [PATCH net-next] tun: relax check on eth_get_headlen() return value
@ 2017-10-17 17:07 Eric Dumazet
2017-10-19 12:18 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Eric Dumazet @ 2017-10-17 17:07 UTC (permalink / raw)
To: David Miller; +Cc: netdev, Petar Penkov
From: Eric Dumazet <edumazet@google.com>
syzkaller hit the WARN() in tun_get_user(), providing skb
with payload in fragments only, and nothing in skb->head
GRO layer is fine with this, so relax the check.
Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
drivers/net/tun.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 57e4c31fa84adc4d9af6ab69a87feac23a8b034e..c64ec19af9b73744270f5cdb922d0f0c1c8f4443 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1737,7 +1737,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
/* Exercise flow dissector code path. */
u32 headlen = eth_get_headlen(skb->data, skb_headlen(skb));
- if (headlen > skb_headlen(skb) || headlen < ETH_HLEN) {
+ if (unlikely(headlen > skb_headlen(skb))) {
this_cpu_inc(tun->pcpu_stats->rx_dropped);
napi_free_frags(&tfile->napi);
mutex_unlock(&tfile->napi_mutex);
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH net-next] tun: relax check on eth_get_headlen() return value
2017-10-17 17:07 [PATCH net-next] tun: relax check on eth_get_headlen() return value Eric Dumazet
@ 2017-10-19 12:18 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2017-10-19 12:18 UTC (permalink / raw)
To: eric.dumazet; +Cc: netdev, peterpenkov96
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, 17 Oct 2017 10:07:44 -0700
> From: Eric Dumazet <edumazet@google.com>
>
> syzkaller hit the WARN() in tun_get_user(), providing skb
> with payload in fragments only, and nothing in skb->head
>
> GRO layer is fine with this, so relax the check.
>
> Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
Applied.
^ permalink raw reply [flat|nested] 2+ messages in thread
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