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authorHelge Deller <deller@gmx.de>2022-06-29 15:53:55 +0200
committerHelge Deller <deller@gmx.de>2022-07-07 10:52:21 +0200
commit6c11df58fd1ac0aefcb3b227f72769272b939e56 (patch)
treecfffe612addc6988e362bdb639c56e384a092718 /drivers
parentfbcon: Prevent that screen size is smaller than font size (diff)
downloadlinux-6c11df58fd1ac0aefcb3b227f72769272b939e56.tar.xz
linux-6c11df58fd1ac0aefcb3b227f72769272b939e56.zip
fbmem: Check virtual screen sizes in fb_set_var()
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@gmx.de> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: stable@vger.kernel.org # v5.4+
Diffstat (limited to 'drivers')
-rw-r--r--drivers/video/fbdev/core/fbmem.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 7dc6848a96bb..7ee6eb2fa715 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1017,6 +1017,16 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
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;