[dpdk-dev] [PATCH] power: fix use-after-free in pstate code

[Burakov, Anatoly]

On 07-Apr-21 5:31 PM, Burakov, Anatoly wrote:
> On 07-Apr-21 4:56 PM, Anatoly Burakov wrote:
>> Previous fix has addressed the incorrect handling of `base_frequency`
>> file, but has added a use-after-free error due to the fact that all
>> further code paths will lead to an `fclose()` call at the end, so the
>> additional `fclose()` call right after processing the file was
>> unnecessary.
>>
>> Coverity issue: 369901
>>
>> Fixes: 8a5febaac4f7 ("power: fix P-state base frequency handling")
>>
>> Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
>> ---
> 
> Actually, self-nack, because this:
> 
>      snprintf(fullpath_min, sizeof(fullpath_min), POWER_SYSFILE_MIN_FREQ,
>              pi->lcore_id);
>      f_min = fopen(fullpath_min, "rw+");
>      FOPEN_OR_ERR_RET(f_min, -1);
> 
>      snprintf(fullpath_max, sizeof(fullpath_max), POWER_SYSFILE_MAX_FREQ,
>              pi->lcore_id);
>      f_max = fopen(fullpath_max, "rw+");
>      if (f_max == NULL)
>          fclose(f_min);
>      FOPEN_OR_ERR_RET(f_max, -1);
> 
> comes after, and will leak the f_base descriptor. Closing it and setting 
> it to NULL seems like a better solution.
> 

Actually no, scratch that, it doesn't :) that's before. So, patch should 
be OK.

-- 
Thanks,
Anatoly