This is a note to let you know that I've just added the patch titled
fbmem: Check virtual screen sizes in fb_set_var()
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fbmem-check-virtual-screen-sizes-in-fb_set_var.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 6c11df58fd1ac0aefcb3b227f72769272b939e56 Mon Sep 17 00:00:00 2001
From: Helge Deller <deller@xxxxxx>
Date: Wed, 29 Jun 2022 15:53:55 +0200
Subject: fbmem: Check virtual screen sizes in fb_set_var()
From: Helge Deller <deller@xxxxxx>
commit 6c11df58fd1ac0aefcb3b227f72769272b939e56 upstream.
Verify that the fbdev or drm driver correctly adjusted the virtual
screen sizes. On failure report the failing driver and reject the screen
size change.
Signed-off-by: Helge Deller <deller@xxxxxx>
Reviewed-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v5.4+
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/video/fbdev/core/fbmem.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1014,6 +1014,16 @@ fb_set_var(struct fb_info *info, struct
if (ret)
return ret;
+ /* verify that virtual resolution >= physical resolution */
+ if (var->xres_virtual < var->xres ||
+ var->yres_virtual < var->yres) {
+ pr_warn("WARNING: fbcon: Driver '%s' missed to adjust virtual screen size (%ux%u vs. %ux%u)\n",
+ info->fix.id,
+ var->xres_virtual, var->yres_virtual,
+ var->xres, var->yres);
+ return -EINVAL;
+ }
+
if ((var->activate & FB_ACTIVATE_MASK) != FB_ACTIVATE_NOW)
return 0;
Patches currently in stable-queue which might be from deller@xxxxxx are
queue-5.4/fbcon-disallow-setting-font-bigger-than-screen-size.patch
queue-5.4/fbmem-check-virtual-screen-sizes-in-fb_set_var.patch
queue-5.4/fbcon-prevent-that-screen-size-is-smaller-than-font-size.patch
queue-5.4/fbdev-fbmem-fix-logo-center-image-dx-issue.patch
queue-5.4/video-of_display_timing.h-include-errno.h.patch
