[PATCH] fbcon: rotate upside down crash

Stefani Seibold
2009-07-28T08:02:18Z

Attached is a bug fix for the frame console.

The current frame buffer console upside down functionality will crash
using a font which has not a width of multiple by 8.

The following 1 liner will fix the rotate_ud() function,

ChangeLog:
Fix the rotate_ud() function not to crash in case of a font which has not a width of multiple by 8: The
inner loop of the font pixel copy should not access a bit outside the font memory area. Subtract the shift
offset from the font width will prevent this.

fbcon_rotate.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Signed-off-by: Stefani Seibold <stefani@seibold.net>

--- linux-2.6.31-rc4.orig/drivers/video/console/fbcon_rotate.h 2009-06-10 05:05:27.000000000 +0200
+++ linux-2.6.31-rc4/drivers/video/console/fbcon_rotate.h 2009-07-24 20:37:31.000000000 +0200
@@ -45,7 +45,7 @@
width = (width + 7) & ~7;

for (i = 0; i < height; i++) {
- for (j = 0; j < width; j++) {
+ for (j = 0; j < width - shift; j++) {
if (pattern_test_bit(j, i, width, in))
pattern_set_bit(width - (1 + j + shift),
height - (1 + i),