Re: [PATCH] tests/intel/perf_pmu: Fix double free of drpc in test_rc6

["Anirban, Sk" <sk.anirban@intel.com>]

Hi Krishnaveni,

On 09-09-2026 11:59 am, krishnaveni.palanisamy@intel.com wrote:
> From: Krishnaveni Palanisamy <krishnaveni.palanisamy@intel.com>
>
> test_rc6() frees the 'drpc' buffer returned by igt_sysfs_get() at the
> end of each phase (initial wakeup, post-S3, post-idle) but leaves the
> pointer dangling. If a subsequent phase is skipped or returns early,
> the same pointer could be freed again, resulting in a
> "double free detected in tcache" abort from glibc when the test exits.
>
> Set drpc to NULL after each free() so the pointer cannot be reused
> accidentally.
>
> Signed-off-by: Krishnaveni Palanisamy <krishnaveni.palanisamy@intel.com>
> ---
>   tests/intel/perf_pmu.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/tests/intel/perf_pmu.c b/tests/intel/perf_pmu.c
> index 1e389958f..f48e1af57 100644
> --- a/tests/intel/perf_pmu.c
> +++ b/tests/intel/perf_pmu.c
> @@ -1766,6 +1766,7 @@ test_rc6(int gem_fd, unsigned int gt, unsigned int num_gt, unsigned int flags)
>   					    ts[1] - ts[0],
>   					    tolerance, drpc);
>   		free(drpc);
> +		drpc=NULL;
spaces required around that '='
>   	}
>   
>   	if (flags & TEST_S3) {
> @@ -1806,6 +1807,7 @@ test_rc6(int gem_fd, unsigned int gt, unsigned int num_gt, unsigned int flags)
>   					    ts[1] - ts[0],
>   					    tolerance, drpc);
>   		free(drpc);
> +		drpc=NULL;
same
>   	}
>   
>   	/* Wake up device and check no RC6. */
> @@ -1847,6 +1849,7 @@ test_rc6(int gem_fd, unsigned int gt, unsigned int num_gt, unsigned int flags)
>   						    ts[1] - ts[0],
>   						    tolerance, drpc);
>   		free(drpc);
> +		drpc=NULL;

same here.

Thanks,
Anirban

>   	}
>   }
>