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 241811308CB; Fri, 2 Feb 2024 18:42:35 +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=1706899355; cv=none; b=LlsYfGFxBTGuGEZU5rvHl9RRptWxzcQIutcrzRu7qF4Z62wAEUdSySsf+iyeYxSwy2nSq4BcStc3FdQkAPRUU1xRAwaeQVDOj2KnAFTIrRplARcHvvJovTmxJzAu8DPUJ+G4cTS9aqxmo6yNdmzYq077tVJENmyZC0rq1uTTt9o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706899355; c=relaxed/simple; bh=RDplX8i+eCVHA9vQdejr+iOAe9siIjDUJX+BZWX9FEI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NsTVIMZnEfQN/dNwWk4jliYu1pP6W3nzhRXDvvp1fU9qJv2C+9RnJs/2wbUEL5X4mNiwRXGGJcopAv293g88rDpug4+G7CVQAQ/lHPLZIrx3je6eoQrh4aRpmbb4Bn2VaC3GEvxvo3b/E4bhMw0KCL9GwEPbcPXvK0BRHe7oaXg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iyD4/w0R; 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="iyD4/w0R" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 12997C43390; Fri, 2 Feb 2024 18:42:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706899355; bh=RDplX8i+eCVHA9vQdejr+iOAe9siIjDUJX+BZWX9FEI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iyD4/w0RLglKwcgZ51NTLdu6NUkkC2c15j+NvFGfhJKpKzSR7UO9pR3IFs6cuVT8H pQMtGhu9AbjbNzofsRgJhgApalTFUISrU1i/IMdpuhE/jDkeUmCIOYZqM3rG+sX2YV /hQP/7CxefiiwEx5CX+XauFojOqRkEXACvcfQXNojL9H6u1BMfsGrgWigb4QFEYv+1 CLBconZuvW4EMVPVaUSaNFd8fQstuLd4l6BrO63SfaVzQ2TnrV9cs1Bujem+EeXf5k 3nEhdASJFuXKZ/LoINoYRJEtyAPR0wPDIP6FH9jDrpWaxZMZ5lgRd5VDKNiOTE6u4u WqFyt56euorDQ== 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 4.19 3/5] fbdev: savage: Error out if pixclock equals zero Date: Fri, 2 Feb 2024 13:42:24 -0500 Message-ID: <20240202184229.542298-3-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: stable@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 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 c09d7426cd92..d9eafdb89cea 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