[PATCH] drm/xe: Fix uninitialized pointer read in xe_vm_bind_kernel_bo

[Cavitt, Jonathan]

-----Original Message-----
From: Intel-xe <intel-xe-bounces at lists.freedesktop.org> On Behalf Of Dheeraj Reddy Jonnalagadda
Sent: Thursday, February 6, 2025 5:47 AM
To: De Marchi, Lucas <lucas.demarchi at intel.com>; thomas.hellstrom at linux.intel.com; Vivi, Rodrigo <rodrigo.vivi at intel.com>
Cc: airlied at gmail.com; simona at ffwll.ch; intel-xe at lists.freedesktop.org; dri-devel at lists.freedesktop.org; linux-kernel at vger.kernel.org; Dheeraj Reddy Jonnalagadda <dheeraj.linuxdev at gmail.com>
Subject: [PATCH] drm/xe: Fix uninitialized pointer read in xe_vm_bind_kernel_bo
> 
> xe_vm_bind_kernel_bo() declares the variable fence without initializing
> it. If an error occurs before fence is assigned a valid value, the
> function may return an uninitialized pointer.
> 
> Specifically, this can happen if:
> 
> - vm_bind_ioctl_ops_create() fails, leading to release_vm_lock error
>   path
> 
> Initialize fence to NULL at declaration.
> 
> Fixes: dcdd6b84d9ac ("drm/xe/pxp: Allocate PXP execution resources")
> Signed-off-by: Dheeraj Reddy Jonnalagadda <dheeraj.linuxdev at gmail.com>

Fair enough.
Reviewed-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
-Jonathan Cavitt

> ---
>  drivers/gpu/drm/xe/xe_vm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index d664f2e418b2..b6ca53ede904 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -3184,7 +3184,7 @@ struct dma_fence *xe_vm_bind_kernel_bo(struct xe_vm *vm, struct xe_bo *bo,
>  {
>  	struct xe_vma_ops vops;
>  	struct drm_gpuva_ops *ops = NULL;
> -	struct dma_fence *fence;
> +	struct dma_fence *fence = NULL;
>  	int err;
>  
>  	xe_bo_get(bo);
> -- 
> 2.34.1
> 
>