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 AF50F14FF89; Fri, 2 Feb 2024 18:41:36 +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=1706899296; cv=none; b=AM/QKKyv0VQIu0hW/Lj6V8OtaDSq5N2Z6O6GHKgZ1Outbkgby3sefQYN6EJiDsEOAoFcWrOUzVBLKE7NSOHzJ2z/tMeMJhJv0idZdk6fBQwR5m4IAWNHHcra6T5TAsUh7FTuL+pJQJVoHiH7yvcG7nMWvqOmGm0MCXdcvtLE78A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706899296; c=relaxed/simple; bh=39r6KwcwEavhQc/YC8RhALPOF3PfKMR2Uu9B0zwyiJY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YLFp4VzVSE8NLq7H6DuZnsmO+97v7jGE+WU8W+kfdK6bCBY0o2B29/ul+oWdnYyAV6EmEFu9qxjPvSvLxexiGTuuu3qXg8r6LoC9/C4lXAcQ1rDAFl+6Zyf96vG+ZST5Lj02TWrjtSGEMy8G7UK1cgjNt3TOGoWa1YCNyNf6WZg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bHS7UpSc; 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="bHS7UpSc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9DAF5C433F1; Fri, 2 Feb 2024 18:41:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706899296; bh=39r6KwcwEavhQc/YC8RhALPOF3PfKMR2Uu9B0zwyiJY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bHS7UpScMaV47Iz9QJ/bQ5w+ZXXx8XaolBHcbVzcsav5Iqy+tL5hWTelit9YBqKC7 HpOm4uOT16TIFP9AWN/xL8h+NniSwv79SOKCCsjIwV0r4XY7yp8UfZuKpX41cVVy94 h95n62wrfZVXp1GX2GDY8mqv62+AVLTn3bhLhs8V1PxfWR+U+ZGULmdu6TbxlACHQG +qYseo2bc4BSB6gxGUxq39Sr1+/p0bFbPw8VKMay0a5UUagspXOr1Q6qdK5EXCGY8A MNd3AvZSCDwdgZp4z4aHSA9CBiMG4xSerGzP+3OUtjhzMBcPs/pVtstwRzH6opdnGf C3lAsY/GeELzw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Fullway Wang , Helge Deller , Sasha Levin , adaplas@gmail.com, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 5.15 03/11] fbdev: savage: Error out if pixclock equals zero Date: Fri, 2 Feb 2024 13:41:17 -0500 Message-ID: <20240202184130.541736-3-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240202184130.541736-1-sashal@kernel.org> References: <20240202184130.541736-1-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 5.15.148 Content-Transfer-Encoding: 8bit From: Fullway Wang [ 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 Signed-off-by: Helge Deller Signed-off-by: Sasha Levin --- 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 0ac750cc5ea1..94ebd8af50cf 100644 --- a/drivers/video/fbdev/savage/savagefb_driver.c +++ b/drivers/video/fbdev/savage/savagefb_driver.c @@ -868,6 +868,9 @@ 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