Re: [PATCH] drm/xe/svm: fix dereferencing error pointer in drm_gpusvm_range_alloc()

[Matthew Brost <matthew.brost@intel.com>]

On Sun, Mar 23, 2025 at 05:49:06AM -0700, Harshit Mogalapalli wrote:
> xe_svm_range_alloc() returns ERR_PTR(-ENOMEM) on failure and there is a
> dereference of "range" after that:
> 
> 	-->     range->gpusvm = gpusvm;
> 
> In xe_svm_range_alloc(), when memory allocation fails return NULL
> instead to handle this situation.
> 
> Fixes: 99624bdff867 ("drm/gpusvm: Add support for GPU Shared Virtual Memory")
> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> Closes: https://lore.kernel.org/all/adaef4dd-5866-48ca-bc22-4a1ddef20381@stanley.mountain/
> Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>

Reviewed-by: Matthew Brost <matthew.brost@intel.com>

> ---
> This is based on static analysis and only compile tested.
> ---
>  drivers/gpu/drm/xe/xe_svm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
> index 52e04e7e343f..a79df8cf1f36 100644
> --- a/drivers/gpu/drm/xe/xe_svm.c
> +++ b/drivers/gpu/drm/xe/xe_svm.c
> @@ -80,7 +80,7 @@ xe_svm_range_alloc(struct drm_gpusvm *gpusvm)
>  
>  	range = kzalloc(sizeof(*range), GFP_KERNEL);
>  	if (!range)
> -		return ERR_PTR(-ENOMEM);
> +		return NULL;
>  
>  	INIT_LIST_HEAD(&range->garbage_collector_link);
>  	xe_vm_get(gpusvm_to_vm(gpusvm));
> -- 
> 2.39.3
>