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* ipv6: fix headroom calculation in udp6_ufo_fragment
@ 2013-12-13 13:01 Mark Hambleton
  2013-12-13 13:14 ` Mark Brown
  2013-12-13 13:34 ` Hannes Frederic Sowa
  0 siblings, 2 replies; 7+ messages in thread
From: Mark Hambleton @ 2013-12-13 13:01 UTC (permalink / raw)
  To: 'Pravin B Shelar', 'Saran Neti',
	'David S. Miller', 'Greg Kroah-Hartman',
	'Hannes Frederic Sowa'
  Cc: Mark Brown (broonie@linaro.org), 'netdev@vger.kernel.org',
	'stable@vger.kernel.org'

Hi, 

Following a recent commit to LTS and upstream  I see the following warning emitted on an ARM32 build:

net/ipv6/udp_offload.c: In function 'udp6_ufo_fragment':
net/ipv6/udp_offload.c:88:22: error: comparison between pointer and integer [-Werror]
  if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
                      ^
cc1: all warnings being treated as errors
make[2]: *** [net/ipv6/udp_offload.o] Error 1
make[1]: *** [net/ipv6] Error 2

 The commit made the following changes:

-       if (skb_headroom(skb) < (tnl_hlen + frag_hdr_sz)) {
+       if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {

Now, because of some defines in skbuff.h :

#if BITS_PER_LONG > 32
#define NET_SKBUFF_DATA_USES_OFFSET 1
#endif

#ifdef NET_SKBUFF_DATA_USES_OFFSET
typedef unsigned int sk_buff_data_t;
#else
typedef unsigned char *sk_buff_data_t;
#endif

On an ARM32 system sk_buff_data_t would be a pointer (long being 32 bits), meaning that skb->mac_header is a pointer and that  you are comparing a pointer against a length, which doesn't look like it is correct to me?

I can see how this works when NET_SKBUFF_DATA_USES_OFFSET is defined, but is there a way to do this that works for both cases?

Hope this makes sense, 

Mark

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: ipv6: fix headroom calculation in udp6_ufo_fragment
  2013-12-13 13:01 ipv6: fix headroom calculation in udp6_ufo_fragment Mark Hambleton
@ 2013-12-13 13:14 ` Mark Brown
  2013-12-13 13:34 ` Hannes Frederic Sowa
  1 sibling, 0 replies; 7+ messages in thread
From: Mark Brown @ 2013-12-13 13:14 UTC (permalink / raw)
  To: Mark Hambleton
  Cc: 'Pravin B Shelar', 'Saran Neti',
	'David S. Miller', 'Greg Kroah-Hartman',
	'Hannes Frederic Sowa', 'netdev@vger.kernel.org',
	'stable@vger.kernel.org'

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On Fri, Dec 13, 2013 at 01:01:59PM +0000, Mark Hambleton wrote:

> Following a recent commit to LTS and upstream  I see the following
> warning emitted on an ARM32 build:

That's 024abeeced731 in LTS and 0e033e04c2678 upstream (ipv6: fix
headroom calculation in udp6_ufo_fragment).

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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: ipv6: fix headroom calculation in udp6_ufo_fragment
  2013-12-13 13:01 ipv6: fix headroom calculation in udp6_ufo_fragment Mark Hambleton
  2013-12-13 13:14 ` Mark Brown
@ 2013-12-13 13:34 ` Hannes Frederic Sowa
  2013-12-13 13:42   ` Mark Brown
  1 sibling, 1 reply; 7+ messages in thread
From: Hannes Frederic Sowa @ 2013-12-13 13:34 UTC (permalink / raw)
  To: Mark Hambleton
  Cc: 'Pravin B Shelar', 'Saran Neti',
	'David S. Miller', 'Greg Kroah-Hartman',
	Mark Brown (broonie@linaro.org), 'netdev@vger.kernel.org',
	'stable@vger.kernel.org'

On Fri, Dec 13, 2013 at 01:01:59PM +0000, Mark Hambleton wrote:
> Hi, 
> 
> Following a recent commit to LTS and upstream  I see the following warning emitted on an ARM32 build:
> 
> net/ipv6/udp_offload.c: In function 'udp6_ufo_fragment':
> net/ipv6/udp_offload.c:88:22: error: comparison between pointer and integer [-Werror]
>   if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
>                       ^
> cc1: all warnings being treated as errors
> make[2]: *** [net/ipv6/udp_offload.o] Error 1
> make[1]: *** [net/ipv6] Error 2
> 
>  The commit made the following changes:
> 
> -       if (skb_headroom(skb) < (tnl_hlen + frag_hdr_sz)) {
> +       if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
> 
> Now, because of some defines in skbuff.h :
> 
> #if BITS_PER_LONG > 32
> #define NET_SKBUFF_DATA_USES_OFFSET 1
> #endif
> 
> #ifdef NET_SKBUFF_DATA_USES_OFFSET
> typedef unsigned int sk_buff_data_t;
> #else
> typedef unsigned char *sk_buff_data_t;
> #endif
> 
> On an ARM32 system sk_buff_data_t would be a pointer (long being 32 bits), meaning that skb->mac_header is a pointer and that  you are comparing a pointer against a length, which doesn't look like it is correct to me?
> 
> I can see how this works when NET_SKBUFF_DATA_USES_OFFSET is defined, but is there a way to do this that works for both cases?

Sorry, I don't know which version the LTS kernel is. Upstream does not use
sk_buff_data_t for mac_header any more.

Something like that might help:

(skb_mac_header(skb) < skb->head + tnl_hlen + frag_hdr_sz)

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: ipv6: fix headroom calculation in udp6_ufo_fragment
  2013-12-13 13:34 ` Hannes Frederic Sowa
@ 2013-12-13 13:42   ` Mark Brown
  2013-12-13 14:12     ` Hannes Frederic Sowa
  0 siblings, 1 reply; 7+ messages in thread
From: Mark Brown @ 2013-12-13 13:42 UTC (permalink / raw)
  To: Mark Hambleton, 'Pravin B Shelar', 'Saran Neti',
	'David S. Miller', 'Greg Kroah-Hartman',
	'netdev@vger.kernel.org',
	'stable@vger.kernel.org'

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On Fri, Dec 13, 2013 at 02:34:53PM +0100, Hannes Frederic Sowa wrote:

> Sorry, I don't know which version the LTS kernel is. Upstream does not use
> sk_buff_data_t for mac_header any more.

This is with v3.10.

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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: ipv6: fix headroom calculation in udp6_ufo_fragment
  2013-12-13 13:42   ` Mark Brown
@ 2013-12-13 14:12     ` Hannes Frederic Sowa
  2013-12-13 15:00       ` Mark Hambleton
  2013-12-17 20:01       ` David Miller
  0 siblings, 2 replies; 7+ messages in thread
From: Hannes Frederic Sowa @ 2013-12-13 14:12 UTC (permalink / raw)
  To: Mark Brown
  Cc: Mark Hambleton, 'Pravin B Shelar', 'Saran Neti',
	'David S. Miller', 'Greg Kroah-Hartman',
	'netdev@vger.kernel.org',
	'stable@vger.kernel.org'

On Fri, Dec 13, 2013 at 01:42:05PM +0000, Mark Brown wrote:
> On Fri, Dec 13, 2013 at 02:34:53PM +0100, Hannes Frederic Sowa wrote:
> 
> > Sorry, I don't know which version the LTS kernel is. Upstream does not use
> > sk_buff_data_t for mac_header any more.
> 
> This is with v3.10.

The change happend in 3.11. So I guess it was an oversight while backporting.
Following patch should help and should get backported to all stable kernels
<= 3.10.

[PATCH stable] ipv6: fix illegal mac_header comparison on 32bit

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
---

Patch intended for stable kernel <= 3.10.

 net/ipv6/udp_offload.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index e7359f9..e15a357 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -90,7 +90,7 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
 
 		/* Check if there is enough headroom to insert fragment header. */
 		tnl_hlen = skb_tnl_header_len(skb);
-		if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
+		if (skb_mac_header(skb) < skb->head + tnl_hlen + frag_hdr_sz) {
 			if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
 				goto out;
 		}
-- 
1.8.3.1

^ permalink raw reply related	[flat|nested] 7+ messages in thread

* RE: ipv6: fix headroom calculation in udp6_ufo_fragment
  2013-12-13 14:12     ` Hannes Frederic Sowa
@ 2013-12-13 15:00       ` Mark Hambleton
  2013-12-17 20:01       ` David Miller
  1 sibling, 0 replies; 7+ messages in thread
From: Mark Hambleton @ 2013-12-13 15:00 UTC (permalink / raw)
  To: Hannes Frederic Sowa, Mark Brown
  Cc: 'Pravin B Shelar', 'Saran Neti',
	'David S. Miller', 'Greg Kroah-Hartman',
	'netdev@vger.kernel.org',
	'stable@vger.kernel.org'

Thanks!

That fixes the warning and looks like it will work.

Mark

-----Original Message-----
From: Hannes Frederic Sowa [mailto:hannes@stressinduktion.org] 
Sent: 13 December 2013 14:12
To: Mark Brown
Cc: Mark Hambleton; 'Pravin B Shelar'; 'Saran Neti'; 'David S. Miller'; 'Greg Kroah-Hartman'; 'netdev@vger.kernel.org'; 'stable@vger.kernel.org'
Subject: Re: ipv6: fix headroom calculation in udp6_ufo_fragment

On Fri, Dec 13, 2013 at 01:42:05PM +0000, Mark Brown wrote:
> On Fri, Dec 13, 2013 at 02:34:53PM +0100, Hannes Frederic Sowa wrote:
> 
> > Sorry, I don't know which version the LTS kernel is. Upstream does not use
> > sk_buff_data_t for mac_header any more.
> 
> This is with v3.10.

The change happend in 3.11. So I guess it was an oversight while backporting.
Following patch should help and should get backported to all stable kernels
<= 3.10.

[PATCH stable] ipv6: fix illegal mac_header comparison on 32bit

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
---

Patch intended for stable kernel <= 3.10.

 net/ipv6/udp_offload.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index e7359f9..e15a357 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -90,7 +90,7 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
 
 		/* Check if there is enough headroom to insert fragment header. */
 		tnl_hlen = skb_tnl_header_len(skb);
-		if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
+		if (skb_mac_header(skb) < skb->head + tnl_hlen + frag_hdr_sz) {
 			if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
 				goto out;
 		}
-- 
1.8.3.1




^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: ipv6: fix headroom calculation in udp6_ufo_fragment
  2013-12-13 14:12     ` Hannes Frederic Sowa
  2013-12-13 15:00       ` Mark Hambleton
@ 2013-12-17 20:01       ` David Miller
  1 sibling, 0 replies; 7+ messages in thread
From: David Miller @ 2013-12-17 20:01 UTC (permalink / raw)
  To: hannes; +Cc: broonie, mark.hambleton, pshelar, Saran.Neti, gregkh, netdev,
	stable

From: Hannes Frederic Sowa <hannes@stressinduktion.org>
Date: Fri, 13 Dec 2013 15:12:27 +0100

> On Fri, Dec 13, 2013 at 01:42:05PM +0000, Mark Brown wrote:
>> On Fri, Dec 13, 2013 at 02:34:53PM +0100, Hannes Frederic Sowa wrote:
>> 
>> > Sorry, I don't know which version the LTS kernel is. Upstream does not use
>> > sk_buff_data_t for mac_header any more.
>> 
>> This is with v3.10.
> 
> The change happend in 3.11. So I guess it was an oversight while backporting.
> Following patch should help and should get backported to all stable kernels
> <= 3.10.
> 
> [PATCH stable] ipv6: fix illegal mac_header comparison on 32bit
> 
> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>

Queued up for -stable, thanks Hannes.

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2013-12-17 20:01 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
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2013-12-13 13:01 ipv6: fix headroom calculation in udp6_ufo_fragment Mark Hambleton
2013-12-13 13:14 ` Mark Brown
2013-12-13 13:34 ` Hannes Frederic Sowa
2013-12-13 13:42   ` Mark Brown
2013-12-13 14:12     ` Hannes Frederic Sowa
2013-12-13 15:00       ` Mark Hambleton
2013-12-17 20:01       ` David Miller

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