linux-kernel - Re: [v2] cpufreq: amd-pstate: fix the memory to free after epp exist

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date: Tue, 14 May 2024 03:30:45 -0500
From: "Limonciello, Mario" <mario.limonciello@....com>
To: "Yuan, Perry" <Perry.Yuan@....com>,
 "zhida312@...look.com" <zhida312@...look.com>
Cc: andypma <andypma@...cent.com>, "Huang, Ray" <Ray.Huang@....com>,
 "Shenoy, Gautham Ranjal" <gautham.shenoy@....com>,
 "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
 "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
 "viresh.kumar@...aro.org" <viresh.kumar@...aro.org>,
 "rafael@...nel.org" <rafael@...nel.org>
Subject: Re: [v2] cpufreq: amd-pstate: fix the memory to free after epp exist



On 5/14/2024 3:24 AM, Yuan, Perry wrote:
> [AMD Official Use Only - AMD Internal Distribution Only]
> 
>> -----Original Message-----
>> From: zhida312@...look.com <zhida312@...look.com>
>> Sent: Tuesday, May 14, 2024 2:43 PM
>> To: rafael@...nel.org; viresh.kumar@...aro.org
>> Cc: andypma <andypma@...cent.com>; Huang, Ray
>> <Ray.Huang@....com>; Shenoy, Gautham Ranjal
>> <gautham.shenoy@....com>; Limonciello, Mario
>> <Mario.Limonciello@....com>; Yuan, Perry <Perry.Yuan@....com>; linux-
>> pm@...r.kernel.org; linux-kernel@...r.kernel.org
>> Subject: [v2] cpufreq: amd-pstate: fix the memory to free after epp exist
>>
>> From: andypma <andypma.tencent.com>
>>
>> the cpudata memory from kzmalloc in epp init function is not free after epp
>> exist, so we should free it.
>>
>> Signed-off-by: andypma <andypma@...cent.com>
> 
> Looks like you need to fix the format of the `Signed-off-by` line in your commit, you need to ensure that it follows the correct format of including your full name and email address. Here's how you can fix it:
> 
> Signed-off-by: Your Full Name <your_email@...mple.com>
> 
> So maybe you want to change like this.
> Signed-off-by: Andy Pma <andypma@...cent.com>
> 
> Perry.
> 
>>
>> Changes since v1:
>>        check whether it is empty before releasing.
>>        set driver_data is NULL after free.
>> ---
>>   drivers/cpufreq/amd-pstate.c | 7 +++++++
>>   1 file changed, 7 insertions(+)
>>
>> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
>> index 6a342b0c0140..e100c5b6c9b2 100644
>> --- a/drivers/cpufreq/amd-pstate.c
>> +++ b/drivers/cpufreq/amd-pstate.c
>> @@ -1441,6 +1441,13 @@ static int amd_pstate_epp_cpu_init(struct
>> cpufreq_policy *policy)
>>
>>   static int amd_pstate_epp_cpu_exit(struct cpufreq_policy *policy)  {
>> +     struct amd_cpudata *cpudata = policy->driver_data;
>> +
>> +     if(cpudata) {

You want a space after the if

But isn't it safe to call kfree(cpudata) even if cpudata was already NULL?

>> +             kfree(cpudata);
>> +             policy->driver_data = NULL;
>> +     }
>> +
>>        pr_debug("CPU %d exiting\n", policy->cpu);
>>        return 0;
>>   }
>> --
>> 2.33.0
>