Hi
Am 10.09.24 um 09:22 schrieb Roger Pau Monné:
On Mon, Sep 09, 2024 at 10:09:16PM -0400, Jason Andryuk wrote:
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: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
The other option would be to re-instate the NULL check in
video_is_primary_device()
I do think this is needed, or at least an explanation. The commit
message in f178e96de7f0 doesn't mention anything about
video_is_primary_device() not allowing being passed a NULL device
(like it was possible with fb_is_primary_device()).
Otherwise callers of video_is_primary_device() would need to be
adjusted to check for device != NULL.
The helper expects a non-NULL pointer. We might want to document this.
Best regards
Thomas
Thanks, Roger.
--
--
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)
