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 A48C5C0015E for ; Thu, 29 Jun 2023 18:49:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233005AbjF2StG (ORCPT ); Thu, 29 Jun 2023 14:49:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60802 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232977AbjF2Sst (ORCPT ); Thu, 29 Jun 2023 14:48:49 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA06D3588 for ; Thu, 29 Jun 2023 11:48:37 -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 98502615C8 for ; Thu, 29 Jun 2023 18:48:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ABCF4C433C0; Thu, 29 Jun 2023 18:48:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1688064507; bh=jGuwhosPqR+8otm7NNUjp6JfVxgUTuY+fcRDuzgsDJY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=daSOAZKWGbgEk0VuYiGEdutqkV5HoEdClnJZH8js6Bt3AS+gFOLrXnxq8o3z69fB4 g3YHr5AZT+dRPxf+zmpLZCmX6TYXgYzOvCwYwcQQ+BMmWG52DTNj2LIFWt7Oxi6ND+ Lxn5hpwDMCLwC67S8MyKjPbWW6LNC/mVu5IEagZU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhang Shurong , Helge Deller Subject: [PATCH 6.4 25/28] fbdev: fix potential OOB read in fast_imageblit() Date: Thu, 29 Jun 2023 20:44:13 +0200 Message-ID: <20230629184152.872120836@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230629184151.888604958@linuxfoundation.org> References: <20230629184151.888604958@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhang Shurong commit c2d22806aecb24e2de55c30a06e5d6eb297d161d upstream. 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: Greg Kroah-Hartman --- drivers/video/fbdev/core/sysimgblt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/video/fbdev/core/sysimgblt.c +++ b/drivers/video/fbdev/core/sysimgblt.c @@ -189,7 +189,7 @@ static void fast_imageblit(const struct 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;