linux-kernel - [PATCH] drm/bochs: avoided potential integer overflow

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>] [day] [month] [year] [list]

Message-Id: <20240313112518.2030805-1-korotkov.maxim.s@gmail.com>
Date: Wed, 13 Mar 2024 14:25:18 +0300
From: Maxim Korotkov <korotkov.maxim.s@...il.com>
To: Gerd Hoffmann <kraxel@...hat.com>
Cc: Maxim Korotkov <korotkov.maxim.s@...il.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Daniel Vetter <daniel@...ll.ch>,
	virtualization@...ts.linux.dev,
	dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org,
	Maxim Korotkov <m.korotkov@...uritycode.ru>
Subject: [PATCH] drm/bochs: avoided potential integer overflow

if the bochs_dispi_read() function returns a value between
0x8000 and 0xFFFF, then an overflow may occurs.

Found by Security Code and Linux Verification Center (linuxtesting.org)

Signed-off-by: Maxim Korotkov <m.korotkov@...uritycode.ru>
---
 drivers/gpu/drm/tiny/bochs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tiny/bochs.c b/drivers/gpu/drm/tiny/bochs.c
index c23c9f0cf49c..ad31049f9779 100644
--- a/drivers/gpu/drm/tiny/bochs.c
+++ b/drivers/gpu/drm/tiny/bochs.c
@@ -240,7 +240,7 @@ static int bochs_hw_init(struct drm_device *dev)
 
 	id = bochs_dispi_read(bochs, VBE_DISPI_INDEX_ID);
 	mem = bochs_dispi_read(bochs, VBE_DISPI_INDEX_VIDEO_MEMORY_64K)
-		* 64 * 1024;
+		* mul_u32_u32(64, 1024);
 	if ((id & 0xfff0) != VBE_DISPI_ID0) {
 		DRM_ERROR("ID mismatch\n");
 		return -ENODEV;
-- 
2.34.1