This bug fix is not required for OVS use cases. But is it
nice to keep function consistent with upstream implementation.
Upstream commit:
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 <ava...@odin.com>
Signed-off-by: Pravin B Shelar <pshe...@nicira.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Upstream: 31b33dfb0a1 ("skbuff: Fix skb checksum partial check");
Signed-off-by: Pravin B Shelar <pshe...@nicira.com>
---
datapath/linux/compat/include/linux/skbuff.h | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/datapath/linux/compat/include/linux/skbuff.h
b/datapath/linux/compat/include/linux/skbuff.h
index 0edcbfd..ab54a83 100644
--- a/datapath/linux/compat/include/linux/skbuff.h
+++ b/datapath/linux/compat/include/linux/skbuff.h
@@ -371,18 +371,19 @@ 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;
}
#define skb_pull_rcsum rpl_skb_pull_rcsum
static inline unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int
len)
{
+ unsigned char *data = skb->data;
+
BUG_ON(len > skb->len);
- skb->len -= len;
- BUG_ON(skb->len < skb->data_len);
- skb_postpull_rcsum(skb, skb->data, len);
- return skb->data += len;
+ __skb_pull(skb, len);
+ skb_postpull_rcsum(skb, data, len);
+ return skb->data;
}
#endif
--
1.8.3.1
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