viafb: improve pitch handling

commit 936a3f770b8de7042d793272f008ef1bb08522e9 upstream.

This patch adds checks for minimum and maximum pitch size to prevent
invalid settings which could otherwise crash the machine. Also the
alignment is done in a slightly more readable way.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/video/via/via_modesetting.h b/drivers/video/via/via_modesetting.h
index ae35cfdeb37cd0de853c9f1c82b1fc7614011fed..013884543e91a88f37e30806ee8da6fd31821d79 100644 (file)
--- a/drivers/video/via/via_modesetting.h
+++ b/drivers/video/via/via_modesetting.h
@@ -28,6 +28,11 @@
 
 #include <linux/types.h>
 
+
+#define VIA_PITCH_SIZE (1<<3)
+#define VIA_PITCH_MAX  0x3FF8
+
+
 void via_set_primary_address(u32 addr);
 void via_set_secondary_address(u32 addr);
 void via_set_primary_pitch(u32 pitch);

diff --git a/drivers/video/via/viafbdev.c b/drivers/video/via/viafbdev.c
index e19dc43d2bcbb558fe45db7811e2731fc969a602..09fa57cea8446e06dc1c99cf4cd250818c64a692 100644 (file)
--- a/drivers/video/via/viafbdev.c
+++ b/drivers/video/via/viafbdev.c
@@ -151,7 +151,8 @@ static void viafb_update_fix(struct fb_info *info)
 
        info->fix.visual =
                bpp == 8 ? FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_TRUECOLOR;
-       info->fix.line_length = (info->var.xres_virtual * bpp / 8 + 7) & ~7;
+       info->fix.line_length = ALIGN(info->var.xres_virtual * bpp / 8,
+               VIA_PITCH_SIZE);
 }
 
 static void viafb_setup_fixinfo(struct fb_fix_screeninfo *fix,
@@ -238,8 +239,12 @@ static int viafb_check_var(struct fb_var_screeninfo *var,
                depth = 24;
 
        viafb_fill_var_color_info(var, depth);
-       line = (var->xres_virtual * var->bits_per_pixel / 8 + 7) & ~7;
-       if (line * var->yres_virtual > ppar->memsize)
+       if (var->xres_virtual < var->xres)
+               var->xres_virtual = var->xres;
+
+       line = ALIGN(var->xres_virtual * var->bits_per_pixel / 8,
+               VIA_PITCH_SIZE);
+       if (line > VIA_PITCH_MAX || line * var->yres_virtual > ppar->memsize)
                return -EINVAL;
 
        /* Based on var passed in to calculate the refresh,