linux-kernel - [PATCH] Revert "fbcon: Use kzalloc() in fbcon_prepare

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <98b79fbdde69a4a203096eb9c8801045c5a055fb.1690218016.git.geert+renesas@glider.be>
Date:   Mon, 24 Jul 2023 19:03:48 +0200
From:   Geert Uytterhoeven <geert+renesas@...der.be>
To:     Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>,
        Daniel Vetter <daniel@...ll.ch>, Helge Deller <deller@....de>
Cc:     Kees Cook <keescook@...omium.org>,
        Alexander Potapenko <glider@...gle.com>,
        Marco Elver <elver@...gle.com>,
        Dmitry Vyukov <dvyukov@...gle.com>,
        kasan-dev <kasan-dev@...glegroups.com>,
        linux-fbdev@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org,
        Geert Uytterhoeven <geert+renesas@...der.be>
Subject: [PATCH] Revert "fbcon: Use kzalloc() in fbcon_prepare_logo()"

This reverts commit a6a00d7e8ffd78d1cdb7a43f1278f081038c638f.

The syzbot report turned out to be a false possitive, caused by a KMSAN
problem.  Indeed, after allocating the buffer, it is fully initialized
using scr_memsetw().  Hence there is no point in allocating zeroed
memory, while this does incur some overhead.

Closes: https://lore.kernel.org/r/CAMuHMdUH4CU9EfoirSxjivg08FDimtstn7hizemzyQzYeq6b6g@mail.gmail.com/
Signed-off-by: Geert Uytterhoeven <geert+renesas@...der.be>
---
 drivers/video/fbdev/core/fbcon.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 8e76bc246b3871b0..0246948f3c81a7a6 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -577,7 +577,7 @@ static void fbcon_prepare_logo(struct vc_data *vc, struct fb_info *info,
 		if (scr_readw(r) != vc->vc_video_erase_char)
 			break;
 	if (r != q && new_rows >= rows + logo_lines) {
-		save = kzalloc(array3_size(logo_lines, new_cols, 2),
+		save = kmalloc(array3_size(logo_lines, new_cols, 2),
 			       GFP_KERNEL);
 		if (save) {
 			int i = min(cols, new_cols);
-- 
2.34.1