From: Helge Deller deller@gmx.de
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@gmx.de Reviewed-by: Geert Uytterhoeven geert@linux-m68k.org Cc: stable@vger.kernel.org # v5.4+ Link: https://lore.kernel.org/all/20220706150253.2186-1-deller@gmx.de/ [sudip: adjust context] Signed-off-by: Chen Jun chenjun102@huawei.com --- drivers/video/fbdev/core/fbmem.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index e83b7ca500b7..90d918c78f04 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) goto done;
+ /* 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) { struct fb_var_screeninfo old_var; struct fb_videomode mode;