fbcon: Use array3_size() helper in scr_memcpyw()

Use array3_size() helper instead of the open-coded version in scr_memcpyw()
and scr_memsetw(). These sorts of multiplication factors need to be wrapped
in array3_size().

This issue was found with the help of Coccinelle and, audited and fixed
manually.

Addresses-KSPP-ID: https://github.com/KSPP/linux/issues/83
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200615231542.GA20470@embeddedor

diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 9d28a8e..6af2734 100644 (file)
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -639,7 +639,7 @@ static void fbcon_prepare_logo(struct vc_data *vc, struct fb_info *info,
                               GFP_KERNEL);
                if (save) {
                        int i = cols < new_cols ? cols : new_cols;
-                       scr_memsetw(save, erase, logo_lines * new_cols * 2);
+                       scr_memsetw(save, erase, array3_size(logo_lines, new_cols, 2));
                        r = q - step;
                        for (cnt = 0; cnt < logo_lines; cnt++, r += i)
                                scr_memcpyw(save + cnt * new_cols, r, 2 * i);
@@ -676,7 +676,7 @@ static void fbcon_prepare_logo(struct vc_data *vc, struct fb_info *info,
                q = (unsigned short *) (vc->vc_origin +
                                        vc->vc_size_row *
                                        rows);
-               scr_memcpyw(q, save, logo_lines * new_cols * 2);
+               scr_memcpyw(q, save, array3_size(logo_lines, new_cols, 2));
                vc->vc_y += logo_lines;
                vc->vc_pos += logo_lines * vc->vc_size_row;
                kfree(save);