| Message ID | 1443486265-2246-1-git-send-email-pshelar@nicira.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Mon, Sep 28, 2015 at 5:24 PM, Pravin B Shelar <pshelar@nicira.com> wrote: > 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> > --- > This and 6ae459bda patches needs to be backported to stable. > --- > include/linux/skbuff.h | 2 +- > 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 2b0a30a..4398411 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -2708,7 +2708,7 @@ 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 dad4dd3..fab4599 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -2958,11 +2958,12 @@ EXPORT_SYMBOL_GPL(skb_append_pagefrags); > */ > 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; > } Nice cleanup in skb_pull_rcsum, but does this affect other calls to skb_postpull_rcsum? > EXPORT_SYMBOL_GPL(skb_pull_rcsum); > > -- > 1.7.1 > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Sep 28, 2015 at 5:46 PM, Tom Herbert <tom@herbertland.com> wrote: > On Mon, Sep 28, 2015 at 5:24 PM, Pravin B Shelar <pshelar@nicira.com> wrote: >> 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> >> --- >> This and 6ae459bda patches needs to be backported to stable. >> --- >> include/linux/skbuff.h | 2 +- >> 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 2b0a30a..4398411 100644 >> --- a/include/linux/skbuff.h >> +++ b/include/linux/skbuff.h >> @@ -2708,7 +2708,7 @@ 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 dad4dd3..fab4599 100644 >> --- a/net/core/skbuff.c >> +++ b/net/core/skbuff.c >> @@ -2958,11 +2958,12 @@ EXPORT_SYMBOL_GPL(skb_append_pagefrags); >> */ >> 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; >> } > > Nice cleanup in skb_pull_rcsum, but does this affect other calls to > skb_postpull_rcsum? > I checked all callers to skb_postpull_rcsum(). Basically there are two type of caller. First case is pulling headers which is same as this case, for example pull skb then call postpull_rcsum() to update csum. Second case is where update checksum while poping a header, for example pop vlan header. All these case works fine with the change. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Pravin B Shelar <pshelar@nicira.com> Date: Mon, 28 Sep 2015 17:24:25 -0700 > 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> > --- > This and 6ae459bda patches needs to be backported to stable. Applied and both queued up for -stable, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 2b0a30a..4398411 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2708,7 +2708,7 @@ 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 dad4dd3..fab4599 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2958,11 +2958,12 @@ EXPORT_SYMBOL_GPL(skb_append_pagefrags); */ 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);
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> --- This and 6ae459bda patches needs to be backported to stable. --- include/linux/skbuff.h | 2 +- net/core/skbuff.c | 9 +++++---- 2 files changed, 6 insertions(+), 5 deletions(-)