fbcon: fix rotate upside down crash

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.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/video/console/fbcon_rotate.h b/drivers/video/console/fbcon_rotate.h
index 75be5ce53dc541f74b15d014b2e652d6a627664c..e233444cda664783d055b372929cafd2f4ac2e89 100644 (file)
--- a/drivers/video/console/fbcon_rotate.h
+++ b/drivers/video/console/fbcon_rotate.h
@@ -45,7 +45,7 @@ static inline void rotate_ud(const char *in, char *out, u32 width, u32 height)
        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),