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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19CDFC5519F for ; Tue, 17 Nov 2020 13:45:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B245B246AA for ; Tue, 17 Nov 2020 13:45:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="gLcMKfyu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733079AbgKQNoo (ORCPT ); Tue, 17 Nov 2020 08:44:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:51990 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732806AbgKQNkJ (ORCPT ); Tue, 17 Nov 2020 08:40:09 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3B38E207BC; Tue, 17 Nov 2020 13:40:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605620408; bh=aeWeB7GhISJbMU5/XDoRIlrYHmcH3VZQgdT6UK1SHt0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gLcMKfyuvZhYVtjqXhEda7n/1f0tYjsAJuiQOntGS4B1bXU7Sxw1sYI85gzCUzipo wsm+iuUdd4yN/DG8qbTyQ3YEdD/2FKovaZBAJWPh0yM6IyK3wJyKot51uws57GWqBb SIQvSLw3j98hKGw+pGsTrcXEN11QmacnqoJnw+SE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chen Yu , Masami Hiramatsu , "Steven Rostedt (VMware)" Subject: [PATCH 5.9 208/255] bootconfig: Extend the magic check range to the preceding 3 bytes Date: Tue, 17 Nov 2020 14:05:48 +0100 Message-Id: <20201117122149.056573069@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201117122138.925150709@linuxfoundation.org> References: <20201117122138.925150709@linuxfoundation.org> User-Agent: quilt/0.66 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: Masami Hiramatsu commit 50b8a742850fce7293bed45753152c425f7e931b upstream. Since Grub may align the size of initrd to 4 if user pass initrd from cpio, we have to check the preceding 3 bytes as well. Link: https://lkml.kernel.org/r/160520205132.303174.4876760192433315429.stgit@devnote2 Cc: stable@vger.kernel.org Fixes: 85c46b78da58 ("bootconfig: Add bootconfig magic word for indicating bootconfig explicitly") Reported-by: Chen Yu Tested-by: Chen Yu Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- init/main.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) --- a/init/main.c +++ b/init/main.c @@ -267,14 +267,24 @@ static void * __init get_boot_config_fro u32 size, csum; char *data; u32 *hdr; + int i; if (!initrd_end) return NULL; data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN; - if (memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN)) - return NULL; + /* + * Since Grub may align the size of initrd to 4, we must + * check the preceding 3 bytes as well. + */ + for (i = 0; i < 4; i++) { + if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN)) + goto found; + data--; + } + return NULL; +found: hdr = (u32 *)(data - 8); size = hdr[0]; csum = hdr[1];