From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1D3BA15DEF9; Fri, 2 Feb 2024 18:42:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706899358; cv=none; b=FrvXK3fNA/I6nlw1z/ypNcyzSY0ZsGRksQZ6u+MwUlavxULHE5mAnCwb7bmq6DkkgYbUEIWVqD1mCJ7FjbHkKeWGZM3fqqB44Lo53A15Gytmxm9y7gK0oHeAwaS8IC29sNIWqNz9R6K/0/Zq4j1vYmDh1Xkekzg0s4eXSyb07fQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706899358; c=relaxed/simple; bh=uvhYev15j5sKSpk4W36dY35o9B0FZ/iIo2RY+WGvCdg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Zb1b/TmMJ2uLXmeH2P4vXXqkjXnuc8oC1b5Gd77yQiyoXhQV2Mtb1VKh+x4stvvkLZtMUJrPtuVJc7DPypg9rTs7PXrnd58p/j7+E7q7dvolU7sl+JrjFQhw6J3lcvgukN6unt3ThAXEMgKhTmtP7q0mrQT3QKUdXAxo3CX+7P0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gtmOCbON; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gtmOCbON" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 89DEAC433C7; Fri, 2 Feb 2024 18:42:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706899357; bh=uvhYev15j5sKSpk4W36dY35o9B0FZ/iIo2RY+WGvCdg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gtmOCbON1oxGBijgXNE1xXgOfJd920SfAxewvQTnK493WNdY8cP+1OY4zqz0tgnWW Lm9Df06BDyq4GALDdeoww/Ew8OeE0NJ9DrnDgL14mevDJmVwFYObHgBGGsxk87bhAW sft/LQNJEqVQ6DdTvuP50KNaKZBYimqTj57HE5IvSXYDICiwNcTrpcEWR69kjyzKhh nhViWu2ctSoHX/Yotv9wY40OZgj/Qvv5LKpctKmnBWkJCrys+DTpmLGbk7OeZ0zDHL MuAP0lm+om+oZppvcT31bOqHdJxYRtiwrWFHWRlpp5Bua3iVPIXTHkqc3l5d368vIs hzTEqi0XTn/LQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Fullway Wang , Helge Deller , Sasha Levin , tzimmermann@suse.de, sam@ravnborg.org, javierm@redhat.com, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 4.19 4/5] fbdev: sis: Error out if pixclock equals zero Date: Fri, 2 Feb 2024 13:42:25 -0500 Message-ID: <20240202184229.542298-4-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240202184229.542298-1-sashal@kernel.org> References: <20240202184229.542298-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 4.19.306 Content-Transfer-Encoding: 8bit From: Fullway Wang [ 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 Signed-off-by: Helge Deller Signed-off-by: Sasha Levin --- 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 20aff9005978..b7f9da690db2 100644 --- a/drivers/video/fbdev/sis/sis_main.c +++ b/drivers/video/fbdev/sis/sis_main.c @@ -1488,6 +1488,8 @@ 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