[Qemu-devel] [PATCH v2] net: ne2000: check ring buffer control registers

[Qemu-devel] [PATCH v2] net: ne2000: check ring buffer control registers

[P J P]

From: Prasad J Pandit <pjp@fedoraproject.org>

Ne2000 NIC uses ring buffer of NE2000_MEM_SIZE(49152)
bytes to process network packets. Registers PSTART & PSTOP
define ring buffer size & location. Setting these registers
to invalid values could lead to infinite loop or OOB r/w
access issues. Add check to avoid it.

Reported-by: Yang Hongke <yanghongke@huawei.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
 hw/net/ne2000.c | 4 ++++
 1 file changed, 4 insertions(+)

Update per review:
  -> https://lists.gnu.org/archive/html/qemu-devel/2016-02/msg05522.html

diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c
index b032212..ced4666 100644
--- a/hw/net/ne2000.c
+++ b/hw/net/ne2000.c
@@ -154,6 +154,10 @@ static int ne2000_buffer_full(NE2000State *s)
 {
     int avail, index, boundary;
 
+    if (s->stop <= s->start) {
+        return 1;
+    }
+
     index = s->curpag << 8;
     boundary = s->boundary << 8;
     if (index < boundary)
-- 
2.5.0

Re: [Qemu-devel] [PATCH v2] net: ne2000: check ring buffer control registers

[Jason Wang]

On 02/24/2016 02:11 PM, P J P wrote:
> From: Prasad J Pandit <pjp@fedoraproject.org>
>
> Ne2000 NIC uses ring buffer of NE2000_MEM_SIZE(49152)
> bytes to process network packets. Registers PSTART & PSTOP
> define ring buffer size & location. Setting these registers
> to invalid values could lead to infinite loop or OOB r/w
> access issues. Add check to avoid it.
>
> Reported-by: Yang Hongke <yanghongke@huawei.com>
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
> ---
>  hw/net/ne2000.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> Update per review:
>   -> https://lists.gnu.org/archive/html/qemu-devel/2016-02/msg05522.html
>
> diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c
> index b032212..ced4666 100644
> --- a/hw/net/ne2000.c
> +++ b/hw/net/ne2000.c
> @@ -154,6 +154,10 @@ static int ne2000_buffer_full(NE2000State *s)
>  {
>      int avail, index, boundary;
>  
> +    if (s->stop <= s->start) {
> +        return 1;
> +    }
> +
>      index = s->curpag << 8;
>      boundary = s->boundary << 8;
>      if (index < boundary)

Hongke, would you mind to test this patch to see if it fixes your issue
and add a "Tested-by" tag?

Thanks

[Qemu-devel] 答复: [PATCH v2] net: ne2000: check ring buffer control registers

[yanghongke]

Good day to you!

	After my test, I find that the issue is fixed with this patch.
	When receiving packet, ne2000_buffer_full return 1, ne2000_receive immediately return -1,so it avoid infinite loop or OOB r/w access issues.

-----邮件原件-----
发件人: Jason Wang [mailto:jasowang@redhat.com] 
发送时间: 2016年2月24日 16:13
收件人: P J P; Qemu Developers
抄送: yanghongke; Prasad J Pandit
主题: Re: [PATCH v2] net: ne2000: check ring buffer control registers



On 02/24/2016 02:11 PM, P J P wrote:
> From: Prasad J Pandit <pjp@fedoraproject.org>
>
> Ne2000 NIC uses ring buffer of NE2000_MEM_SIZE(49152) bytes to process 
> network packets. Registers PSTART & PSTOP define ring buffer size & 
> location. Setting these registers to invalid values could lead to 
> infinite loop or OOB r/w access issues. Add check to avoid it.
>
> Reported-by: Yang Hongke <yanghongke@huawei.com>
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
> ---
>  hw/net/ne2000.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> Update per review:
>   -> 
> https://lists.gnu.org/archive/html/qemu-devel/2016-02/msg05522.html
>
> diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c index b032212..ced4666 
> 100644
> --- a/hw/net/ne2000.c
> +++ b/hw/net/ne2000.c
> @@ -154,6 +154,10 @@ static int ne2000_buffer_full(NE2000State *s)  {
>      int avail, index, boundary;
>  
> +    if (s->stop <= s->start) {
> +        return 1;
> +    }
> +
>      index = s->curpag << 8;
>      boundary = s->boundary << 8;
>      if (index < boundary)

Hongke, would you mind to test this patch to see if it fixes your issue and add a "Tested-by" tag?

Thanks

Re: [Qemu-devel] 答复: [PATCH v2] net: ne2000: check ring buffer control registers

[Jason Wang]

On 02/24/2016 05:25 PM, yanghongke wrote:
> Good day to you!
>
> 	After my test, I find that the issue is fixed with this patch.
> 	When receiving packet, ne2000_buffer_full return 1, ne2000_receive immediately return -1,so it avoid infinite loop or OOB r/w access issues.

Thanks for the testing. (Btw please use bottom posting on the list).

Apply the patch with your "Tested-by".

> -----邮件原件-----
> 发件人: Jason Wang [mailto:jasowang@redhat.com] 
> 发送时间: 2016年2月24日 16:13
> 收件人: P J P; Qemu Developers
> 抄送: yanghongke; Prasad J Pandit
> 主题: Re: [PATCH v2] net: ne2000: check ring buffer control registers
>
>
>
> On 02/24/2016 02:11 PM, P J P wrote:
>> From: Prasad J Pandit <pjp@fedoraproject.org>
>>
>> Ne2000 NIC uses ring buffer of NE2000_MEM_SIZE(49152) bytes to process 
>> network packets. Registers PSTART & PSTOP define ring buffer size & 
>> location. Setting these registers to invalid values could lead to 
>> infinite loop or OOB r/w access issues. Add check to avoid it.
>>
>> Reported-by: Yang Hongke <yanghongke@huawei.com>
>> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
>> ---
>>  hw/net/ne2000.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> Update per review:
>>   -> 
>> https://lists.gnu.org/archive/html/qemu-devel/2016-02/msg05522.html
>>
>> diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c index b032212..ced4666 
>> 100644
>> --- a/hw/net/ne2000.c
>> +++ b/hw/net/ne2000.c
>> @@ -154,6 +154,10 @@ static int ne2000_buffer_full(NE2000State *s)  {
>>      int avail, index, boundary;
>>  
>> +    if (s->stop <= s->start) {
>> +        return 1;
>> +    }
>> +
>>      index = s->curpag << 8;
>>      boundary = s->boundary << 8;
>>      if (index < boundary)
> Hongke, would you mind to test this patch to see if it fixes your issue and add a "Tested-by" tag?
>
> Thanks

[Qemu-devel] 答复: [PATCH v2] net: ne2000: check ring buffer control registers

[yanghongke]

On 02/24/2016 02:11 PM, P J P wrote:
> From: Prasad J Pandit <pjp@fedoraproject.org>
>
> Ne2000 NIC uses ring buffer of NE2000_MEM_SIZE(49152) bytes to process 
> network packets. Registers PSTART & PSTOP define ring buffer size & 
> location. Setting these registers to invalid values could lead to 
> infinite loop or OOB r/w access issues. Add check to avoid it.
>
> Reported-by: Yang Hongke <yanghongke@huawei.com>
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
> Tested-by: Yang Hongke <yanghongke@huawei.com>
> ---
>  hw/net/ne2000.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> Update per review:
>   -> 
> https://lists.gnu.org/archive/html/qemu-devel/2016-02/msg05522.html
>
> diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c index b032212..ced4666 
> 100644
> --- a/hw/net/ne2000.c
> +++ b/hw/net/ne2000.c
> @@ -154,6 +154,10 @@ static int ne2000_buffer_full(NE2000State *s)  {
>      int avail, index, boundary;
>  
> +    if (s->stop <= s->start) {
> +        return 1;
> +    }
> +
>      index = s->curpag << 8;
>      boundary = s->boundary << 8;
>      if (index < boundary)

After my test, the issue is fixed with this patch.