From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Fullway Wang <fullwaywang@outlook.com>,
Helge Deller <deller@gmx.de>, Sasha Levin <sashal@kernel.org>,
tzimmermann@suse.de, sam@ravnborg.org, javierm@redhat.com,
linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: [PATCH AUTOSEL 5.10 4/8] fbdev: sis: Error out if pixclock equals zero
Date: Fri, 2 Feb 2024 13:41:48 -0500 [thread overview]
Message-ID: <20240202184156.541981-4-sashal@kernel.org> (raw)
In-Reply-To: <20240202184156.541981-1-sashal@kernel.org>
From: Fullway Wang <fullwaywang@outlook.com>
[ Upstream commit e421946be7d9bf545147bea8419ef8239cb7ca52 ]
The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of pixclock,
it may cause divide-by-zero error.
In sisfb_check_var(), var->pixclock is used as a divisor to caculate
drate before it is checked against zero. Fix this by checking it
at the beginning.
This is similar to CVE-2022-3061 in i740fb which was fixed by
commit 15cf0b8.
Signed-off-by: Fullway Wang <fullwaywang@outlook.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/video/fbdev/sis/sis_main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/video/fbdev/sis/sis_main.c b/drivers/video/fbdev/sis/sis_main.c
index 03c736f6f3d0..e540cb0c5172 100644
--- a/drivers/video/fbdev/sis/sis_main.c
+++ b/drivers/video/fbdev/sis/sis_main.c
@@ -1474,6 +1474,8 @@ sisfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
vtotal = var->upper_margin + var->lower_margin + var->vsync_len;
+ if (!var->pixclock)
+ return -EINVAL;
pixclock = var->pixclock;
if((var->vmode & FB_VMODE_MASK) == FB_VMODE_NONINTERLACED) {
--
2.43.0
prev parent reply other threads:[~2024-02-02 18:42 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20240202184156.541981-1-sashal@kernel.org>
2024-02-02 18:41 ` [PATCH AUTOSEL 5.10 3/8] fbdev: savage: Error out if pixclock equals zero Sasha Levin
2024-02-02 18:41 ` Sasha Levin [this message]
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