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>,
adaplas@gmail.com, linux-fbdev@vger.kernel.org,
dri-devel@lists.freedesktop.org
Subject: [PATCH AUTOSEL 6.1 03/15] fbdev: savage: Error out if pixclock equals zero
Date: Fri, 2 Feb 2024 13:40:40 -0500 [thread overview]
Message-ID: <20240202184057.541411-3-sashal@kernel.org> (raw)
In-Reply-To: <20240202184057.541411-1-sashal@kernel.org>
From: Fullway Wang <fullwaywang@outlook.com>
[ Upstream commit 04e5eac8f3ab2ff52fa191c187a46d4fdbc1e288 ]
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.
Although pixclock is checked in savagefb_decode_var(), but it is not
checked properly in savagefb_probe(). Fix this by checking whether
pixclock is zero in the function savagefb_check_var() before
info->var.pixclock is used as the divisor.
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/savage/savagefb_driver.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/video/fbdev/savage/savagefb_driver.c b/drivers/video/fbdev/savage/savagefb_driver.c
index b7818b652698..a7b63c475f95 100644
--- a/drivers/video/fbdev/savage/savagefb_driver.c
+++ b/drivers/video/fbdev/savage/savagefb_driver.c
@@ -869,6 +869,9 @@ static int savagefb_check_var(struct fb_var_screeninfo *var,
DBG("savagefb_check_var");
+ if (!var->pixclock)
+ return -EINVAL;
+
var->transp.offset = 0;
var->transp.length = 0;
switch (var->bits_per_pixel) {
--
2.43.0
next parent reply other threads:[~2024-02-02 18:41 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20240202184057.541411-1-sashal@kernel.org>
2024-02-02 18:40 ` Sasha Levin [this message]
2024-02-02 18:40 ` [PATCH AUTOSEL 6.1 04/15] fbdev: sis: Error out if pixclock equals zero Sasha Levin
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