From c29390c6dfeee0944ac6b5610ebbe403944378fc Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 11 Mar 2015 18:42:02 -0700 Subject: xps: must clear sender_cpu before forwarding John reported that my previous commit added a regression on his router. This is because sender_cpu & napi_id share a common location, so get_xps_queue() can see garbage and perform an out of bound access. We need to make sure sender_cpu is cleared before doing the transmit, otherwise any NIC busy poll enabled (skb_mark_napi_id()) can trigger this bug. Signed-off-by: Eric Dumazet Reported-by: John Bisected-by: John Fixes: 2bd82484bb4c ("xps: fix xps for stacked devices") Signed-off-by: David S. Miller --- include/linux/skbuff.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 30007afe70b3..f54d6659713a 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -948,6 +948,13 @@ static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from) to->l4_hash = from->l4_hash; }; +static inline void skb_sender_cpu_clear(struct sk_buff *skb) +{ +#ifdef CONFIG_XPS + skb->sender_cpu = 0; +#endif +} + #ifdef NET_SKBUFF_DATA_USES_OFFSET static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) { -- cgit v1.2.3