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

[Burakov, Anatoly]

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.

-- 
Thanks,
Anatoly