From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D604CC83F22 for ; Mon, 28 Aug 2023 10:40:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231716AbjH1KkC (ORCPT ); Mon, 28 Aug 2023 06:40:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231720AbjH1Kjx (ORCPT ); Mon, 28 Aug 2023 06:39:53 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 746A5129 for ; Mon, 28 Aug 2023 03:39:51 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1393B63FFC for ; Mon, 28 Aug 2023 10:39:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29390C433C8; Mon, 28 Aug 2023 10:39:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693219190; bh=qhnCPPjynsGwn4GjTYHijffYxlS9zduO5sU1Zr8LxQQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=emaSPj/qs7dtzFw3ZwbRD1WMUe6rKtcJOyh2NExdqxWtxKOm0MM2t3OG0Sw0NZ2EH f9ApIdzNxDg/lPwWsBdP+DsTzacnpj9nXgm8pNKHNXpPMfdXtn6ct5HX1cbaNIY091 H8uhyz6P7Et0jUgALly8+ko05NVfT3xxYiaku6vo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhang Shurong , Helge Deller , Sasha Levin Subject: [PATCH 5.4 106/158] fbdev: fix potential OOB read in fast_imageblit() Date: Mon, 28 Aug 2023 12:13:23 +0200 Message-ID: <20230828101200.886937835@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101157.322319621@linuxfoundation.org> References: <20230828101157.322319621@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhang Shurong [ Upstream commit c2d22806aecb24e2de55c30a06e5d6eb297d161d ] There is a potential OOB read at fast_imageblit, for "colortab[(*src >> 4)]" can become a negative value due to "const char *s = image->data, *src". This change makes sure the index for colortab always positive or zero. Similar commit: https://patchwork.kernel.org/patch/11746067 Potential bug report: https://groups.google.com/g/syzkaller-bugs/c/9ubBXKeKXf4/m/k-QXy4UgAAAJ Signed-off-by: Zhang Shurong Cc: stable@vger.kernel.org Signed-off-by: Helge Deller Signed-off-by: Sasha Levin --- drivers/video/fbdev/core/sysimgblt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/video/fbdev/core/sysimgblt.c b/drivers/video/fbdev/core/sysimgblt.c index 335e92b813fc4..665ef7a0a2495 100644 --- a/drivers/video/fbdev/core/sysimgblt.c +++ b/drivers/video/fbdev/core/sysimgblt.c @@ -189,7 +189,7 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p, u32 fgx = fgcolor, bgx = bgcolor, bpp = p->var.bits_per_pixel; u32 ppw = 32/bpp, spitch = (image->width + 7)/8; u32 bit_mask, eorx, shift; - const char *s = image->data, *src; + const u8 *s = image->data, *src; u32 *dst; const u32 *tab; size_t tablen; -- 2.40.1