Re: [Intel-gfx] [PATCH] drm/i915: Fix error pointer dereference in i915_gem_do_execbuffer()

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

On Wed, Dec 01, 2021 at 08:48:31PM -0800, Matthew Brost wrote:
> From: Dan Carpenter <dan.carpenter@oracle.com>
> 
> Originally "out_fence" was set using out_fence = sync_file_create() but
> which returns NULL, but now it is set with out_fence = eb_requests_create()
> which returns error pointers.  The error path needs to be modified to
> avoid an Oops in the "goto err_request;" path.
> 
> Fixes: 544460c33821 ("drm/i915: Multi-BB execbuf")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>

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

> ---
>  drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> index 9f7c6ecadb90..6db588b9a30e 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> @@ -3288,6 +3288,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>  	out_fence = eb_requests_create(&eb, in_fence, out_fence_fd);
>  	if (IS_ERR(out_fence)) {
>  		err = PTR_ERR(out_fence);
> +		out_fence = NULL;
>  		if (eb.requests[0])
>  			goto err_request;
>  		else
> -- 
> 2.33.1
>