blob: f02fe255b8365f5cc7f24481f266802c38003a59 [file] [log] [blame]
From 80e08add85117c078c0d1dc0f92441b96189499c Mon Sep 17 00:00:00 2001
From: Arvind Sankar <nivedita@alum.mit.edu>
Date: Tue, 7 Jan 2020 18:04:10 -0500
Subject: [PATCH] x86/sysfb: Fix check for bad VRAM size
commit dacc9092336be20b01642afe1a51720b31f60369 upstream.
When checking whether the reported lfb_size makes sense, the height
* stride result is page-aligned before seeing whether it exceeds the
reported size.
This doesn't work if height * stride is not an exact number of pages.
For example, as reported in the kernel bugzilla below, an 800x600x32 EFI
framebuffer gets skipped because of this.
Move the PAGE_ALIGN to after the check vs size.
Reported-by: Christopher Head <chead@chead.ca>
Tested-by: Christopher Head <chead@chead.ca>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206051
Link: https://lkml.kernel.org/r/20200107230410.2291947-1-nivedita@alum.mit.edu
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/arch/x86/kernel/sysfb_simplefb.c b/arch/x86/kernel/sysfb_simplefb.c
index 01f0e2263b86..298fc1edd9c9 100644
--- a/arch/x86/kernel/sysfb_simplefb.c
+++ b/arch/x86/kernel/sysfb_simplefb.c
@@ -90,11 +90,11 @@ __init int create_simplefb(const struct screen_info *si,
if (si->orig_video_isVGA == VIDEO_TYPE_VLFB)
size <<= 16;
length = mode->height * mode->stride;
- length = PAGE_ALIGN(length);
if (length > size) {
printk(KERN_WARNING "sysfb: VRAM smaller than advertised\n");
return -EINVAL;
}
+ length = PAGE_ALIGN(length);
/* setup IORESOURCE_MEM as framebuffer memory */
memset(&res, 0, sizeof(res));
--
2.7.4