[PATCH 2/5] fbcon: Fix up user-provided virtual screen size

[Helge Deller]

The virtual screen size can't be smaller than the physical screen size.
Based on the general rule that we round up user-provided input if
neccessary, adjust the virtual screen size as well if needed.

Signed-off-by: Helge Deller <deller at gmx.de>
Cc: stable at vger.kernel.org # v5.4+
---
 drivers/video/fbdev/core/fbmem.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index afa2863670f3..e645b96d2700 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1106,6 +1106,11 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
 			return -EFAULT;
 		console_lock();
 		lock_fb_info(info);
+		/* adjust virtual screen size if user missed it */
+		if (var.xres_virtual < var.xres)
+			var.xres_virtual = var.xres;
+		if (var.yres_virtual < var.yres)
+			var.yres_virtual = var.yres;
 		ret = fb_set_var(info, &var);
 		if (!ret)
 			fbcon_update_vcs(info, var.activate & FB_ACTIVATE_ALL);
--
2.35.3