[PATCH] x86: simplefb: avoid overflow

From: Tom Gundersen
Date: Fri Sep 06 2013 - 05:31:25 EST


lfb_size can easily be say 4M, which would make the bitshit overflow and
the test fail.

Signed-off-by: Tom Gundersen <teg@xxxxxxx>
Cc: David Herrmann <dh.herrmann@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
---
arch/x86/kernel/sysfb_simplefb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/sysfb_simplefb.c b/arch/x86/kernel/sysfb_simplefb.c
index 22513e9..fff44a5 100644
--- a/arch/x86/kernel/sysfb_simplefb.c
+++ b/arch/x86/kernel/sysfb_simplefb.c
@@ -72,7 +72,7 @@ __init int create_simplefb(const struct screen_info *si,
* the part that is occupied by the framebuffer */
len = mode->height * mode->stride;
len = PAGE_ALIGN(len);
- if (len > si->lfb_size << 16) {
+ if (len > ((unsigned long) si->lfb_size) << 16) {
printk(KERN_WARNING "sysfb: VRAM smaller than advertised\n");
return -EINVAL;
}
--
1.8.4

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