diff mbox

drm/vkms: off by one in vkms_gem_fault()

Message ID 20180714104951.akt34gkcq54d5pvl@kili.mountain (mailing list archive)
State New, archived
Headers show

Commit Message

Dan Carpenter July 14, 2018, 11:04 a.m. UTC 
The > should be >= so that we don't read one page beyond the end of the
obj->pages[] array.

Fixes: 559e50fd34d1 ("drm/vkms: Add dumb operations")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Comments

Rodrigo Siqueira July 16, 2018, 11:26 a.m. UTC | #1 
Hi Dan,

Thanks for your patch. I checked and tested it, everything is fine.

On 07/14, Dan Carpenter wrote:
> The > should be >= so that we don't read one page beyond the end of the
> obj->pages[] array.
> 
> Fixes: 559e50fd34d1 ("drm/vkms: Add dumb operations")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> diff --git a/drivers/gpu/drm/vkms/vkms_gem.c b/drivers/gpu/drm/vkms/vkms_gem.c
> index c7e38368602b..2cca8c2f260f 100644
> --- a/drivers/gpu/drm/vkms/vkms_gem.c
> +++ b/drivers/gpu/drm/vkms/vkms_gem.c
> @@ -55,7 +55,7 @@ int vkms_gem_fault(struct vm_fault *vmf)
>  	page_offset = (vaddr - vma->vm_start) >> PAGE_SHIFT;
>  	num_pages = DIV_ROUND_UP(obj->gem.size, PAGE_SIZE);
>  
> -	if (page_offset > num_pages)
> +	if (page_offset >= num_pages)
>  		return VM_FAULT_SIGBUS;
>  
>  	ret = -ENOENT;

Reviewed-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
diff mbox

Patch

diff --git a/drivers/gpu/drm/vkms/vkms_gem.c b/drivers/gpu/drm/vkms/vkms_gem.c
index c7e38368602b..2cca8c2f260f 100644
--- a/drivers/gpu/drm/vkms/vkms_gem.c
+++ b/drivers/gpu/drm/vkms/vkms_gem.c
@@ -55,7 +55,7 @@  int vkms_gem_fault(struct vm_fault *vmf)
 	page_offset = (vaddr - vma->vm_start) >> PAGE_SHIFT;
 	num_pages = DIV_ROUND_UP(obj->gem.size, PAGE_SIZE);
 
-	if (page_offset > num_pages)
+	if (page_offset >= num_pages)
 		return VM_FAULT_SIGBUS;
 
 	ret = -ENOENT;