Re: [PATCH] fbdev/xen-fbfront: Assign fb_info->device

[Thomas Zimmermann]

Am 10.09.24 um 04:09 schrieb Jason Andryuk:
> From: Jason Andryuk <jason.andryuk@xxxxxxx>
>
> Probing xen-fbfront faults in video_is_primary_device().  The passed-in
> struct device is NULL since xen-fbfront doesn't assign it and the
> memory is kzalloc()-ed.  Assign fb_info->device to avoid this.
>
> This was exposed by the conversion of fb_is_primary_device() to
> video_is_primary_device() which dropped a NULL check for struct device.
>
> Fixes: f178e96de7f0 ("arch: Remove struct fb_info from video helpers")
> Reported-by: Arthur Borsboom <arthurborsboom@xxxxxxxxx>
> Closes: https://lore.kernel.org/xen-devel/CALUcmUncX=LkXWeiSiTKsDY-cOe8QksWhFvcCneOKfrKd0ZajA@xxxxxxxxxxxxxx/
> Tested-by: Arthur Borsboom <arthurborsboom@xxxxxxxxx>
> CC: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Jason Andryuk <jason.andryuk@xxxxxxx>

Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>

Thanks a lot.

> ---
> The other option would be to re-instate the NULL check in
> video_is_primary_device()
> ---
>   drivers/video/fbdev/xen-fbfront.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/video/fbdev/xen-fbfront.c b/drivers/video/fbdev/xen-fbfront.c
> index 66d4628a96ae..c90f48ebb15e 100644
> --- a/drivers/video/fbdev/xen-fbfront.c
> +++ b/drivers/video/fbdev/xen-fbfront.c
> @@ -407,6 +407,7 @@ static int xenfb_probe(struct xenbus_device *dev,
>   	/* complete the abuse: */
>   	fb_info->pseudo_palette = fb_info->par;
>   	fb_info->par = info;
> +	fb_info->device = &dev->dev;
>   
>   	fb_info->screen_buffer = info->fb;
>   

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)