Re: [PATCH] platform/x86/amd/pmf: Initialize and clean up `cb_mutex`

[Shyam Sundar S K <Shyam-sundar.S-k@amd.com>]

On 2/28/2025 10:06, Shen, Yijun wrote:
> 
> Internal Use - Confidential
>> -----Original Message-----
>> From: Mario Limonciello <superm1@kernel.org>
>> Sent: Friday, February 28, 2025 1:03 AM
>> To: Limonciello, Mario <mario.limonciello@amd.com>; Shyam-sundar.S-
>> k@amd.com; hdegoede@redhat.com; ilpo.jarvinen@linux.intel.com;
>> Patil.Reddy@amd.com
>> Cc: Shen, Yijun <Yijun_Shen@Dell.com>; Richard Gong
>> <richgong@amd.com>; platform-driver-x86@vger.kernel.org
>> Subject: [PATCH] platform/x86/amd/pmf: Initialize and clean up `cb_mutex`
>>
>>
>> [EXTERNAL EMAIL]
>>
>> From: Mario Limonciello <mario.limonciello@amd.com>
>>
>> `cb_mutex` was introduced in commit 9e0894d07072e
>> ("platform/x86/amd/pmf:
>> Enable Custom BIOS Inputs for PMF-TA") to prevent conccurrent access for
>> BIOS inputs. It however isn't initialized and so on use it may lead to a NULL
>> pointer dereference.
>>
>> Add code to initialize on probe and clean up on destroy.
>>
>> Reported-by: Yijun Shen <Yijun.Shen@dell.com>
>> Cc: Richard Gong <richgong@amd.com>
>> Fixes: 9e0894d07072e ("platform/x86/amd/pmf: Enable Custom BIOS Inputs
>> for PMF-TA")
>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> 
> Verified the patch on the issued system, the issue is gone.
> 
> Tested-By: Yijun Shen <Yijun_Shen@Dell.com>
> 

Thank you. Looks good.

Acked-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>

>> ---
>>  drivers/platform/x86/amd/pmf/core.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/platform/x86/amd/pmf/core.c
>> b/drivers/platform/x86/amd/pmf/core.c
>> index 764cc1fe90ae4..a2cb2d5544f5b 100644
>> --- a/drivers/platform/x86/amd/pmf/core.c
>> +++ b/drivers/platform/x86/amd/pmf/core.c
>> @@ -452,6 +452,7 @@ static int amd_pmf_probe(struct platform_device
>> *pdev)
>>
>>       mutex_init(&dev->lock);
>>       mutex_init(&dev->update_mutex);
>> +     mutex_init(&dev->cb_mutex);
>>
>>       apmf_acpi_init(dev);
>>       platform_set_drvdata(pdev, dev);
>> @@ -477,6 +478,7 @@ static void amd_pmf_remove(struct platform_device
>> *pdev)
>>       amd_pmf_dbgfs_unregister(dev);
>>       mutex_destroy(&dev->lock);
>>       mutex_destroy(&dev->update_mutex);
>> +     mutex_destroy(&dev->cb_mutex);
>>       kfree(dev->buf);
>>  }
>>
>> --
>> 2.43.0
>