diff mbox

[2/2] xen-pt: fix Out-of-bounds read

Message ID 1422689277-16032-3-git-send-email-arei.gonglei@huawei.com
State New
Headers show

Commit Message

Gonglei (Arei) Jan. 31, 2015, 7:27 a.m. UTC 
From: Gonglei <arei.gonglei@huawei.com>

The array length of s->real_device.io_regions[] is
"PCI_NUM_REGIONS - 1". Add a check, just make Coverity happy.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
---
 hw/xen/xen_pt_config_init.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Stefano Stabellini Feb. 10, 2015, 6:39 a.m. UTC | #1 
On Sat, 31 Jan 2015, arei.gonglei@huawei.com wrote:
> From: Gonglei <arei.gonglei@huawei.com>
> 
> The array length of s->real_device.io_regions[] is
> "PCI_NUM_REGIONS - 1". Add a check, just make Coverity happy.
> 
> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
> ---
>  hw/xen/xen_pt_config_init.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
> index 710fe50..3c8b0f1 100644
> --- a/hw/xen/xen_pt_config_init.c
> +++ b/hw/xen/xen_pt_config_init.c
> @@ -443,6 +443,11 @@ static int xen_pt_bar_reg_read(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
>          return -1;
>      }
>  
> +    if (index == PCI_ROM_SLOT) {
> +        XEN_PT_ERR(&s->dev, "Internal error: Access violation at ROM BAR.\n");
> +        return -1;
> +    }

Could you please fix the boundaries of the check just above?
Also please avoid using PCI_ROM_SLOT for the array index check, simply
use PCI_NUM_REGIONS.


>      /* use fixed-up value from kernel sysfs */
>      *value = base_address_with_flags(&s->real_device.io_regions[index]);
>  
> -- 
> 1.7.12.4
> 
>
Gonglei (Arei) Feb. 10, 2015, 6:49 a.m. UTC | #2 
On 2015/2/10 14:39, Stefano Stabellini wrote:
> On Sat, 31 Jan 2015, arei.gonglei@huawei.com wrote:
>> From: Gonglei <arei.gonglei@huawei.com>
>>
>> The array length of s->real_device.io_regions[] is
>> "PCI_NUM_REGIONS - 1". Add a check, just make Coverity happy.
>>
>> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
>> ---
>>  hw/xen/xen_pt_config_init.c | 5 +++++
>>  1 file changed, 5 insertions(+)
>>
>> diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
>> index 710fe50..3c8b0f1 100644
>> --- a/hw/xen/xen_pt_config_init.c
>> +++ b/hw/xen/xen_pt_config_init.c
>> @@ -443,6 +443,11 @@ static int xen_pt_bar_reg_read(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
>>          return -1;
>>      }
>>  
>> +    if (index == PCI_ROM_SLOT) {
>> +        XEN_PT_ERR(&s->dev, "Internal error: Access violation at ROM BAR.\n");
>> +        return -1;
>> +    }
> 
> Could you please fix the boundaries of the check just above?
> Also please avoid using PCI_ROM_SLOT for the array index check, simply
> use PCI_NUM_REGIONS.
> 
You meaning is changing the below check:

if (index < 0 || index >= PCI_NUM_REGIONS - 1) {
        XEN_PT_ERR(&s->dev, "Internal error: Invalid BAR index [%d].\n", index);
        return -1;
    }

Isn't it?

Regards,
-Gonglei
Stefano Stabellini Feb. 10, 2015, 7 a.m. UTC | #3 
On Tue, 10 Feb 2015, Gonglei wrote:
> On 2015/2/10 14:39, Stefano Stabellini wrote:
> > On Sat, 31 Jan 2015, arei.gonglei@huawei.com wrote:
> >> From: Gonglei <arei.gonglei@huawei.com>
> >>
> >> The array length of s->real_device.io_regions[] is
> >> "PCI_NUM_REGIONS - 1". Add a check, just make Coverity happy.
> >>
> >> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
> >> ---
> >>  hw/xen/xen_pt_config_init.c | 5 +++++
> >>  1 file changed, 5 insertions(+)
> >>
> >> diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
> >> index 710fe50..3c8b0f1 100644
> >> --- a/hw/xen/xen_pt_config_init.c
> >> +++ b/hw/xen/xen_pt_config_init.c
> >> @@ -443,6 +443,11 @@ static int xen_pt_bar_reg_read(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
> >>          return -1;
> >>      }
> >>  
> >> +    if (index == PCI_ROM_SLOT) {
> >> +        XEN_PT_ERR(&s->dev, "Internal error: Access violation at ROM BAR.\n");
> >> +        return -1;
> >> +    }
> > 
> > Could you please fix the boundaries of the check just above?
> > Also please avoid using PCI_ROM_SLOT for the array index check, simply
> > use PCI_NUM_REGIONS.
> > 
> You meaning is changing the below check:
> 
> if (index < 0 || index >= PCI_NUM_REGIONS - 1) {
>         XEN_PT_ERR(&s->dev, "Internal error: Invalid BAR index [%d].\n", index);
>         return -1;
>     }
> 
> Isn't it?
 
that's right
Gonglei (Arei) Feb. 10, 2015, 7:19 a.m. UTC | #4 
On 2015/2/10 15:00, Stefano Stabellini wrote:
> On Tue, 10 Feb 2015, Gonglei wrote:
>> On 2015/2/10 14:39, Stefano Stabellini wrote:
>>> On Sat, 31 Jan 2015, arei.gonglei@huawei.com wrote:
>>>> From: Gonglei <arei.gonglei@huawei.com>
>>>>
>>>> The array length of s->real_device.io_regions[] is
>>>> "PCI_NUM_REGIONS - 1". Add a check, just make Coverity happy.
>>>>
>>>> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
>>>> ---
>>>>  hw/xen/xen_pt_config_init.c | 5 +++++
>>>>  1 file changed, 5 insertions(+)
>>>>
>>>> diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
>>>> index 710fe50..3c8b0f1 100644
>>>> --- a/hw/xen/xen_pt_config_init.c
>>>> +++ b/hw/xen/xen_pt_config_init.c
>>>> @@ -443,6 +443,11 @@ static int xen_pt_bar_reg_read(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
>>>>          return -1;
>>>>      }
>>>>  
>>>> +    if (index == PCI_ROM_SLOT) {
>>>> +        XEN_PT_ERR(&s->dev, "Internal error: Access violation at ROM BAR.\n");
>>>> +        return -1;
>>>> +    }
>>>
>>> Could you please fix the boundaries of the check just above?
>>> Also please avoid using PCI_ROM_SLOT for the array index check, simply
>>> use PCI_NUM_REGIONS.
>>>
>> You meaning is changing the below check:
>>
>> if (index < 0 || index >= PCI_NUM_REGIONS - 1) {
>>         XEN_PT_ERR(&s->dev, "Internal error: Invalid BAR index [%d].\n", index);
>>         return -1;
>>     }
>>
>> Isn't it?
>  
> that's right
> 
OK, will do, thanks.

Regards,
-Gonglei
diff mbox

Patch

diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
index 710fe50..3c8b0f1 100644
--- a/hw/xen/xen_pt_config_init.c
+++ b/hw/xen/xen_pt_config_init.c
@@ -443,6 +443,11 @@  static int xen_pt_bar_reg_read(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
         return -1;
     }
 
+    if (index == PCI_ROM_SLOT) {
+        XEN_PT_ERR(&s->dev, "Internal error: Access violation at ROM BAR.\n");
+        return -1;
+    }
+
     /* use fixed-up value from kernel sysfs */
     *value = base_address_with_flags(&s->real_device.io_regions[index]);