Re: [PATCH] drivers: nvdimm: fix dereference after free

[Jeff Moyer]

Konstantin Meskhidze <konstantin.meskhidze@xxxxxxxxxx> writes:

> 'nd_pmu->pmu.attr_groups' is dereferenced in function
> 'nvdimm_pmu_free_hotplug_memory' call after it has been freed. Because in
> function 'nvdimm_pmu_free_hotplug_memory' memory pointed by the fields of
> 'nd_pmu->pmu.attr_groups' is deallocated it is necessary to call 'kfree'
> after 'nvdimm_pmu_free_hotplug_memory'.
>
> Co-developed-by: Ivanov Mikhail <ivanov.mikhail1@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@xxxxxxxxxx>
> ---
>  drivers/nvdimm/nd_perf.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/nvdimm/nd_perf.c b/drivers/nvdimm/nd_perf.c
> index 14881c4e0..2b6dc80d8 100644
> --- a/drivers/nvdimm/nd_perf.c
> +++ b/drivers/nvdimm/nd_perf.c
> @@ -307,10 +307,10 @@ int register_nvdimm_pmu(struct nvdimm_pmu *nd_pmu, struct platform_device *pdev)
>  	}
>  
>  	rc = perf_pmu_register(&nd_pmu->pmu, nd_pmu->pmu.name, -1);
>  	if (rc) {
> -		kfree(nd_pmu->pmu.attr_groups);
>  		nvdimm_pmu_free_hotplug_memory(nd_pmu);
> +		kfree(nd_pmu->pmu.attr_groups);
>  		return rc;
>  	}
>  
>  	pr_info("%s NVDIMM performance monitor support registered\n",

Reviewed-by: Jeff Moyer <jmoyer@xxxxxxxxxx>