Re: [v5 11/11] platform/x86/amd/hsmp: Fix potential spectre issue

[Suma Hegde <Suma.Hegde@amd.com>]

Hi Ilpo,

On 8/23/2024 7:24 PM, Ilpo Järvinen wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
>
>
> On Fri, 23 Aug 2024, Suma Hegde wrote:
>
>> Fix below warning caused by smatch by using array_index_nospec()
>> to clamp the index within the range.
>> "warn: potential spectre issue 'plat_dev.sock' [r] (local cap)"
> While the warning have always been bogus for these code paths because
> those are not user controllable values, I suspect the warning might no
> longer trigger at all. I suspect the warning is tied to kstr*() which is
> no longer used.
>
> Also, it should be hsmp_pdev but please retest if this patch can be
> dropped from this series (no need to resend the entire series because of
> that, just mention if this patch can be left out).
I retested with smatch and warning is no more seen. Please drop this 
patch. Thank you.
> --
>   i.
>
>
>> Signed-off-by: Suma Hegde <suma.hegde@amd.com>
>> Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
>> ---
>> Changes since v4:
>> None
>>
>> Changes since v3:
>> None
>>
>> Changes since v2:
>> None
>>
>> Changes since v1:
>> Change plat_dev to hsmp_pdev
>>
>>   drivers/platform/x86/amd/hsmp/acpi.c | 3 +++
>>   drivers/platform/x86/amd/hsmp/plat.c | 3 +++
>>   2 files changed, 6 insertions(+)
>>
>> diff --git a/drivers/platform/x86/amd/hsmp/acpi.c b/drivers/platform/x86/amd/hsmp/acpi.c
>> index f2bfc5981590..16a82b8bce28 100644
>> --- a/drivers/platform/x86/amd/hsmp/acpi.c
>> +++ b/drivers/platform/x86/amd/hsmp/acpi.c
>> @@ -18,6 +18,7 @@
>>   #include <linux/ioport.h>
>>   #include <linux/kstrtox.h>
>>   #include <linux/module.h>
>> +#include <linux/nospec.h>
>>   #include <linux/platform_device.h>
>>   #include <linux/sysfs.h>
>>   #include <linux/uuid.h>
>> @@ -272,6 +273,8 @@ static int init_acpi(struct device *dev)
>>        if (sock_ind >= hsmp_pdev.num_sockets)
>>                return -EINVAL;
>>
>> +     sock_ind = array_index_nospec(sock_ind, hsmp_pdev.num_sockets);
>> +
>>        ret = hsmp_parse_acpi_table(dev, sock_ind);
>>        if (ret) {
>>                dev_err(dev, "Failed to parse ACPI table\n");
>> diff --git a/drivers/platform/x86/amd/hsmp/plat.c b/drivers/platform/x86/amd/hsmp/plat.c
>> index d55c984a9a5a..8fb395e91806 100644
>> --- a/drivers/platform/x86/amd/hsmp/plat.c
>> +++ b/drivers/platform/x86/amd/hsmp/plat.c
>> @@ -15,6 +15,7 @@
>>   #include <linux/device.h>
>>   #include <linux/module.h>
>>   #include <linux/pci.h>
>> +#include <linux/nospec.h>
>>   #include <linux/platform_device.h>
>>   #include <linux/sysfs.h>
>>
>> @@ -79,6 +80,8 @@ static ssize_t hsmp_metric_tbl_read(struct file *filp, struct kobject *kobj,
>>        if (sock_ind >= hsmp_pdev.num_sockets)
>>                return -EINVAL;
>>
>> +     sock_ind = array_index_nospec(sock_ind, hsmp_pdev.num_sockets);
>> +
>>        sock = &hsmp_pdev.sock[sock_ind];
>>        if (!sock)
>>                return -EINVAL;
>>

> Regards,
Suma Hegde