diff options
| author | Pravin B Shelar <pshelar@nicira.com> | 2015-09-28 17:24:25 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-10-27 09:51:49 +0900 |
| commit | 9bdfdea4cc4617aaa3a4f291904fe85e6ca2c9a6 (patch) | |
| tree | 54f74952121ff4c9d4ca61b506569fabffb5e243 | |
| parent | 7017f73bb9837ca8cc5d0a4116aae679bdd8df22 (diff) | |
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 <avagin@odin.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | include/linux/skbuff.h | 2 | ||||
| -rw-r--r-- | net/core/skbuff.c | 9 |
2 files changed, 6 insertions, 5 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 7f04271d7a3b..4307e20a4a4a 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2589,7 +2589,7 @@ 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; } diff --git a/net/core/skbuff.c b/net/core/skbuff.c index a2e4e47b2839..075d2e78c87e 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2976,11 +2976,12 @@ EXPORT_SYMBOL(skb_append_datato_frags); */ 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; } EXPORT_SYMBOL_GPL(skb_pull_rcsum); |