* [PATCH v3 net-next 1/2] net: skbuff: Remove errornous length validation in skb_vlan_pop()
@ 2016-09-20 9:48 Shmulik Ladkani
2016-09-20 9:48 ` [PATCH v3 net-next 2/2] net: skbuff: Coding: Use eth_type_vlan() instead of open coding it Shmulik Ladkani
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Shmulik Ladkani @ 2016-09-20 9:48 UTC (permalink / raw)
To: David S. Miller
Cc: Jiri Pirko, Daniel Borkmann, Pravin Shelar, Eric Dumazet, netdev,
Shmulik Ladkani
In 93515d53b1
"net: move vlan pop/push functions into common code"
skb_vlan_pop was moved from its private location in openvswitch to
skbuff common code.
In case skb has non hw-accel vlan tag, the original 'pop_vlan()' assured
that skb->len is sufficient (if skb->len < VLAN_ETH_HLEN then pop was
considered a no-op).
This validation was moved as is into the new common 'skb_vlan_pop'.
Alas, in its original location (openvswitch), there was a guarantee that
'data' points to the mac_header, therefore the 'skb->len < VLAN_ETH_HLEN'
condition made sense.
However there's no such guarantee in the generic 'skb_vlan_pop'.
For short packets received in rx path going through 'skb_vlan_pop',
this causes 'skb_vlan_pop' to fail pop-ing a valid vlan hdr (in the non
hw-accel case) or to fail moving next tag into hw-accel tag.
Remove the 'skb->len < VLAN_ETH_HLEN' condition entirely:
It is superfluous since inner '__skb_vlan_pop' already verifies there
are VLAN_ETH_HLEN writable bytes at the mac_header.
Note this presents a slight change to skb_vlan_pop() users:
In case total length is smaller than VLAN_ETH_HLEN, skb_vlan_pop() now
returns an error, as opposed to previous "no-op" behavior.
Existing callers (e.g. tc act vlan, ovs) usually drop the packet if
'skb_vlan_pop' fails.
Fixes: 93515d53b1 ("net: move vlan pop/push functions into common code")
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Cc: Pravin Shelar <pshelar@ovn.org>
---
v3: Elaborate log message to explain the change presented to
'skb_vlan_pop' users for packets smaller than VLAN_ETH_HLEN
v2: Remove 'skb->len < VLAN_ETH_HLEN' condition entirely (instead of
testing skb->mac_len as was in v1), suggested by Pravin Shelar
net/core/skbuff.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 7bf82a2..93d6c5c 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4564,9 +4564,8 @@ int skb_vlan_pop(struct sk_buff *skb)
if (likely(skb_vlan_tag_present(skb))) {
skb->vlan_tci = 0;
} else {
- if (unlikely((skb->protocol != htons(ETH_P_8021Q) &&
- skb->protocol != htons(ETH_P_8021AD)) ||
- skb->len < VLAN_ETH_HLEN))
+ if (unlikely(skb->protocol != htons(ETH_P_8021Q) &&
+ skb->protocol != htons(ETH_P_8021AD)))
return 0;
err = __skb_vlan_pop(skb, &vlan_tci);
@@ -4574,9 +4573,8 @@ int skb_vlan_pop(struct sk_buff *skb)
return err;
}
/* move next vlan tag to hw accel tag */
- if (likely((skb->protocol != htons(ETH_P_8021Q) &&
- skb->protocol != htons(ETH_P_8021AD)) ||
- skb->len < VLAN_ETH_HLEN))
+ if (likely(skb->protocol != htons(ETH_P_8021Q) &&
+ skb->protocol != htons(ETH_P_8021AD)))
return 0;
vlan_proto = skb->protocol;
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 net-next 2/2] net: skbuff: Coding: Use eth_type_vlan() instead of open coding it
2016-09-20 9:48 [PATCH v3 net-next 1/2] net: skbuff: Remove errornous length validation in skb_vlan_pop() Shmulik Ladkani
@ 2016-09-20 9:48 ` Shmulik Ladkani
2016-09-20 17:13 ` pravin shelar
2016-09-22 5:36 ` David Miller
2016-09-20 17:12 ` [PATCH v3 net-next 1/2] net: skbuff: Remove errornous length validation in skb_vlan_pop() pravin shelar
2016-09-22 5:36 ` David Miller
2 siblings, 2 replies; 6+ messages in thread
From: Shmulik Ladkani @ 2016-09-20 9:48 UTC (permalink / raw)
To: David S. Miller
Cc: Jiri Pirko, Daniel Borkmann, Pravin Shelar, Eric Dumazet, netdev,
Shmulik Ladkani
Fix 'skb_vlan_pop' to use eth_type_vlan instead of directly comparing
skb->protocol to ETH_P_8021Q or ETH_P_8021AD.
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
---
net/core/skbuff.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 93d6c5c..d6d0da5 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4564,8 +4564,7 @@ int skb_vlan_pop(struct sk_buff *skb)
if (likely(skb_vlan_tag_present(skb))) {
skb->vlan_tci = 0;
} else {
- if (unlikely(skb->protocol != htons(ETH_P_8021Q) &&
- skb->protocol != htons(ETH_P_8021AD)))
+ if (unlikely(!eth_type_vlan(skb->protocol)))
return 0;
err = __skb_vlan_pop(skb, &vlan_tci);
@@ -4573,8 +4572,7 @@ int skb_vlan_pop(struct sk_buff *skb)
return err;
}
/* move next vlan tag to hw accel tag */
- if (likely(skb->protocol != htons(ETH_P_8021Q) &&
- skb->protocol != htons(ETH_P_8021AD)))
+ if (likely(!eth_type_vlan(skb->protocol)))
return 0;
vlan_proto = skb->protocol;
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH v3 net-next 2/2] net: skbuff: Coding: Use eth_type_vlan() instead of open coding it
2016-09-20 9:48 ` [PATCH v3 net-next 2/2] net: skbuff: Coding: Use eth_type_vlan() instead of open coding it Shmulik Ladkani
@ 2016-09-20 17:13 ` pravin shelar
2016-09-22 5:36 ` David Miller
1 sibling, 0 replies; 6+ messages in thread
From: pravin shelar @ 2016-09-20 17:13 UTC (permalink / raw)
To: Shmulik Ladkani
Cc: David S. Miller, Jiri Pirko, Daniel Borkmann, Eric Dumazet,
Linux Kernel Network Developers, Shmulik Ladkani
On Tue, Sep 20, 2016 at 2:48 AM, Shmulik Ladkani
<shmulik.ladkani@ravellosystems.com> wrote:
> Fix 'skb_vlan_pop' to use eth_type_vlan instead of directly comparing
> skb->protocol to ETH_P_8021Q or ETH_P_8021AD.
>
> Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Reviewed-by: Pravin B Shelar <pshelar@ovn.org>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v3 net-next 2/2] net: skbuff: Coding: Use eth_type_vlan() instead of open coding it
2016-09-20 9:48 ` [PATCH v3 net-next 2/2] net: skbuff: Coding: Use eth_type_vlan() instead of open coding it Shmulik Ladkani
2016-09-20 17:13 ` pravin shelar
@ 2016-09-22 5:36 ` David Miller
1 sibling, 0 replies; 6+ messages in thread
From: David Miller @ 2016-09-22 5:36 UTC (permalink / raw)
To: shmulik.ladkani
Cc: jiri, daniel, pshelar, eric.dumazet, netdev, shmulik.ladkani
From: Shmulik Ladkani <shmulik.ladkani@ravellosystems.com>
Date: Tue, 20 Sep 2016 12:48:37 +0300
> Fix 'skb_vlan_pop' to use eth_type_vlan instead of directly comparing
> skb->protocol to ETH_P_8021Q or ETH_P_8021AD.
>
> Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Applied.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v3 net-next 1/2] net: skbuff: Remove errornous length validation in skb_vlan_pop()
2016-09-20 9:48 [PATCH v3 net-next 1/2] net: skbuff: Remove errornous length validation in skb_vlan_pop() Shmulik Ladkani
2016-09-20 9:48 ` [PATCH v3 net-next 2/2] net: skbuff: Coding: Use eth_type_vlan() instead of open coding it Shmulik Ladkani
@ 2016-09-20 17:12 ` pravin shelar
2016-09-22 5:36 ` David Miller
2 siblings, 0 replies; 6+ messages in thread
From: pravin shelar @ 2016-09-20 17:12 UTC (permalink / raw)
To: Shmulik Ladkani
Cc: David S. Miller, Jiri Pirko, Daniel Borkmann, Eric Dumazet,
Linux Kernel Network Developers, Shmulik Ladkani
On Tue, Sep 20, 2016 at 2:48 AM, Shmulik Ladkani
<shmulik.ladkani@ravellosystems.com> wrote:
> In 93515d53b1
> "net: move vlan pop/push functions into common code"
> skb_vlan_pop was moved from its private location in openvswitch to
> skbuff common code.
>
> In case skb has non hw-accel vlan tag, the original 'pop_vlan()' assured
> that skb->len is sufficient (if skb->len < VLAN_ETH_HLEN then pop was
> considered a no-op).
>
> This validation was moved as is into the new common 'skb_vlan_pop'.
>
> Alas, in its original location (openvswitch), there was a guarantee that
> 'data' points to the mac_header, therefore the 'skb->len < VLAN_ETH_HLEN'
> condition made sense.
> However there's no such guarantee in the generic 'skb_vlan_pop'.
>
> For short packets received in rx path going through 'skb_vlan_pop',
> this causes 'skb_vlan_pop' to fail pop-ing a valid vlan hdr (in the non
> hw-accel case) or to fail moving next tag into hw-accel tag.
>
> Remove the 'skb->len < VLAN_ETH_HLEN' condition entirely:
> It is superfluous since inner '__skb_vlan_pop' already verifies there
> are VLAN_ETH_HLEN writable bytes at the mac_header.
>
> Note this presents a slight change to skb_vlan_pop() users:
> In case total length is smaller than VLAN_ETH_HLEN, skb_vlan_pop() now
> returns an error, as opposed to previous "no-op" behavior.
> Existing callers (e.g. tc act vlan, ovs) usually drop the packet if
> 'skb_vlan_pop' fails.
>
> Fixes: 93515d53b1 ("net: move vlan pop/push functions into common code")
> Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
> Cc: Pravin Shelar <pshelar@ovn.org>
> ---
> v3: Elaborate log message to explain the change presented to
> 'skb_vlan_pop' users for packets smaller than VLAN_ETH_HLEN
>
> v2: Remove 'skb->len < VLAN_ETH_HLEN' condition entirely (instead of
> testing skb->mac_len as was in v1), suggested by Pravin Shelar
>
> net/core/skbuff.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
Reviewed-by: Pravin B Shelar <pshelar@ovn.org>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v3 net-next 1/2] net: skbuff: Remove errornous length validation in skb_vlan_pop()
2016-09-20 9:48 [PATCH v3 net-next 1/2] net: skbuff: Remove errornous length validation in skb_vlan_pop() Shmulik Ladkani
2016-09-20 9:48 ` [PATCH v3 net-next 2/2] net: skbuff: Coding: Use eth_type_vlan() instead of open coding it Shmulik Ladkani
2016-09-20 17:12 ` [PATCH v3 net-next 1/2] net: skbuff: Remove errornous length validation in skb_vlan_pop() pravin shelar
@ 2016-09-22 5:36 ` David Miller
2 siblings, 0 replies; 6+ messages in thread
From: David Miller @ 2016-09-22 5:36 UTC (permalink / raw)
To: shmulik.ladkani
Cc: jiri, daniel, pshelar, eric.dumazet, netdev, shmulik.ladkani
From: Shmulik Ladkani <shmulik.ladkani@ravellosystems.com>
Date: Tue, 20 Sep 2016 12:48:36 +0300
> In 93515d53b1
> "net: move vlan pop/push functions into common code"
> skb_vlan_pop was moved from its private location in openvswitch to
> skbuff common code.
>
> In case skb has non hw-accel vlan tag, the original 'pop_vlan()' assured
> that skb->len is sufficient (if skb->len < VLAN_ETH_HLEN then pop was
> considered a no-op).
>
> This validation was moved as is into the new common 'skb_vlan_pop'.
>
> Alas, in its original location (openvswitch), there was a guarantee that
> 'data' points to the mac_header, therefore the 'skb->len < VLAN_ETH_HLEN'
> condition made sense.
> However there's no such guarantee in the generic 'skb_vlan_pop'.
>
> For short packets received in rx path going through 'skb_vlan_pop',
> this causes 'skb_vlan_pop' to fail pop-ing a valid vlan hdr (in the non
> hw-accel case) or to fail moving next tag into hw-accel tag.
>
> Remove the 'skb->len < VLAN_ETH_HLEN' condition entirely:
> It is superfluous since inner '__skb_vlan_pop' already verifies there
> are VLAN_ETH_HLEN writable bytes at the mac_header.
>
> Note this presents a slight change to skb_vlan_pop() users:
> In case total length is smaller than VLAN_ETH_HLEN, skb_vlan_pop() now
> returns an error, as opposed to previous "no-op" behavior.
> Existing callers (e.g. tc act vlan, ovs) usually drop the packet if
> 'skb_vlan_pop' fails.
>
> Fixes: 93515d53b1 ("net: move vlan pop/push functions into common code")
> Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Applied.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2016-09-22 5:36 UTC | newest]
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2016-09-20 9:48 [PATCH v3 net-next 1/2] net: skbuff: Remove errornous length validation in skb_vlan_pop() Shmulik Ladkani
2016-09-20 9:48 ` [PATCH v3 net-next 2/2] net: skbuff: Coding: Use eth_type_vlan() instead of open coding it Shmulik Ladkani
2016-09-20 17:13 ` pravin shelar
2016-09-22 5:36 ` David Miller
2016-09-20 17:12 ` [PATCH v3 net-next 1/2] net: skbuff: Remove errornous length validation in skb_vlan_pop() pravin shelar
2016-09-22 5:36 ` David Miller
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