From f03a8061b5c46dbc6fac58d7933de35ef91841f0 Mon Sep 17 00:00:00 2001 From: Pravin B Shelar Date: Mon, 28 Sep 2015 17:24:25 -0700 Subject: skbuff: Fix skb checksum partial check. [ Upstream commit 31b33dfb0a144469dd805514c9e63f4993729a48 ] Earlier patch 6ae459bda tried to detect void ckecksum partial skb by comparing pull length to checksum offset. But it does not work for all cases since checksum-offset depends on updates to skb->data. Following patch fixes it by validating checksum start offset after skb-data pointer is updated. Negative value of checksum offset start means there is no need to checksum. Fixes: 6ae459bda ("skbuff: Fix skb checksum flag on skb pull") Reported-by: Andrew Vagin Signed-off-by: Pravin B Shelar Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/linux/skbuff.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 19998b8c72f6..993e34774bb1 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2364,7 +2364,7 @@ static inline void skb_postpull_rcsum(struct sk_buff *skb, if (skb->ip_summed == CHECKSUM_COMPLETE) skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); else if (skb->ip_summed == CHECKSUM_PARTIAL && - skb_checksum_start_offset(skb) <= len) + skb_checksum_start_offset(skb) < 0) skb->ip_summed = CHECKSUM_NONE; } -- cgit v1.2.3