From patchwork Thu May 28 09:16:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tetsuhiro Kohada X-Patchwork-Id: 11575359 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7FD8192A for ; Thu, 28 May 2020 09:17:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 618A52145D for ; Thu, 28 May 2020 09:17:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="l0N71qao" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728262AbgE1JRI (ORCPT ); Thu, 28 May 2020 05:17:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728131AbgE1JRH (ORCPT ); Thu, 28 May 2020 05:17:07 -0400 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B330C05BD1E; Thu, 28 May 2020 02:17:07 -0700 (PDT) Received: by mail-pl1-x62a.google.com with SMTP id y11so3045184plt.12; Thu, 28 May 2020 02:17:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=o8hs8Gy4+vcTx/6wICvu/N/ImG6vk07R81c1rqTOhmo=; b=l0N71qao1hvbacif3rtUkOSbER25ThW144oVegNpIDXEuGNq2EaylwS+QnYpRKGNPi cutYH25IZCsN7OnStEqnfjRcGgUh0YLyvny4JfmWV9OYgeDyuh6709H0axsi46bL8o6I TJ9IT9hl/LYVVInLZcajUVSNSWj4eMYXP5355oFzUz1Myy36jU+vfDzWQ3u5cD9TVqrn YfBfjqvUVr9GMFSdPpXv8jOeTspLuh+EKITpkoXORG8ZSoyQT7vMgp3TypS0/otClvxD W5OHzfA339GFDwbMRCC+4uxGACXSrZeH59qpVmYM1BfMSDBGMhQyUn/b+KLoH5kZ7nn8 NFvQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=o8hs8Gy4+vcTx/6wICvu/N/ImG6vk07R81c1rqTOhmo=; b=IzR2Ljyi3zJLmdk/lqxDbU2ehoknzXyVQbJPfAKeOFeuZkwPZBM17sIW9iKPIhRJHf pEkMw0s1AgaoILXCij1uB9GpzqGf+zsyyvagr7OPJq4nMpthF4bKqFd8W0evH/H4j3Hz +liERFBMJmH51aZHzN/8edJ4hTFhDhwnBrinnWElXcxieLPyWXJe413uY8HHgszqqSNK D1BA8CyIpRlHYQq8RuyScg0zj8J5iFBRf9j8DM7uqfKS98WI2JENkWAn2eYnvb7XhLdS BRX2U9r6axSC1hwt9JA3CxWr4v71O4x7a/NdQ3WNKDRNaOziwVCjXCUJjoo7Nk8j9gCa JCGA== X-Gm-Message-State: AOAM532FTTB/6SuFF9EHut74sVzSzxh9ilB6SgAQmGVcr3bZoDvkp8I/ zxcZ23Qmi9ujNspfhXlci9U= X-Google-Smtp-Source: ABdhPJwahJ1NP+QNBEmCkE229tlWtT5nT1KzHV6I4UKclk7tpdk6Qk9pj80SLaFPOkSGw+tQe0Ek6w== X-Received: by 2002:a17:90a:4495:: with SMTP id t21mr2797725pjg.185.1590657426953; Thu, 28 May 2020 02:17:06 -0700 (PDT) Received: from dc803.flets-west.jp ([2404:7a87:83e0:f800:295a:ef64:e071:39ab]) by smtp.gmail.com with ESMTPSA id d15sm5856185pjc.0.2020.05.28.02.17.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 May 2020 02:17:06 -0700 (PDT) From: Tetsuhiro Kohada To: kohada.t2@gmail.com Cc: kohada.tetsuhiro@dc.mitsubishielectric.co.jp, mori.takahiro@ab.mitsubishielectric.co.jp, motai.hirotaka@aj.mitsubishielectric.co.jp, Namjae Jeon , Sungjong Seo , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/4 v2] exfat: add boot region verification Date: Thu, 28 May 2020 18:16:03 +0900 Message-Id: <20200528091605.13016-3-kohada.t2@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200528091605.13016-1-kohada.t2@gmail.com> References: <20200528091605.13016-1-kohada.t2@gmail.com> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add Boot-Regions verification specified in exFAT specification. Note that the checksum type is strongly related to the raw structure, so the'u32 'type is used to clarify the number of bits. Signed-off-by: Tetsuhiro Kohada --- Changes in v2: - rebase with patch 'optimize dir-cache' applied - just print a warning when invalid exboot-signature detected - print additional information when invalid boot-checksum detected fs/exfat/exfat_fs.h | 1 + fs/exfat/misc.c | 14 +++++++++++++ fs/exfat/super.c | 49 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 64 insertions(+) diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h index 9673e2d31045..eebbe5a84b2b 100644 --- a/fs/exfat/exfat_fs.h +++ b/fs/exfat/exfat_fs.h @@ -514,6 +514,7 @@ void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts, u8 *tz, __le16 *time, __le16 *date, u8 *time_cs); unsigned short exfat_calc_chksum_2byte(void *data, int len, unsigned short chksum, int type); +u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type); void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync); void exfat_chain_set(struct exfat_chain *ec, unsigned int dir, unsigned int size, unsigned char flags); diff --git a/fs/exfat/misc.c b/fs/exfat/misc.c index ab7f88b1f6d3..b82d2dd5bd7c 100644 --- a/fs/exfat/misc.c +++ b/fs/exfat/misc.c @@ -151,6 +151,20 @@ unsigned short exfat_calc_chksum_2byte(void *data, int len, return chksum; } +u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type) +{ + int i; + u8 *c = (u8 *)data; + + for (i = 0; i < len; i++, c++) { + if (unlikely(type == CS_BOOT_SECTOR && + (i == 106 || i == 107 || i == 112))) + continue; + chksum = ((chksum << 31) | (chksum >> 1)) + *c; + } + return chksum; +} + void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync) { set_bit(EXFAT_SB_DIRTY, &EXFAT_SB(sb)->s_state); diff --git a/fs/exfat/super.c b/fs/exfat/super.c index 95909b4d5e75..381f4394f976 100644 --- a/fs/exfat/super.c +++ b/fs/exfat/super.c @@ -486,6 +486,49 @@ static int exfat_read_boot_sector(struct super_block *sb) return 0; } +static int exfat_verify_boot_region(struct super_block *sb) +{ + struct buffer_head *bh = NULL; + u32 chksum = 0, *p_sig, *p_chksum; + int sn, i; + + /* read boot sector sub-regions */ + for (sn = 0; sn < 11; sn++) { + bh = sb_bread(sb, sn); + if (!bh) + return -EIO; + + if (sn != 0 && sn <= 8) { + /* extended boot sector sub-regions */ + p_sig = (u32 *)&bh->b_data[sb->s_blocksize - 4]; + if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE) + exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x", + sn, le32_to_cpu(*p_sig)); + } + + chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize, + chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR); + brelse(bh); + } + + /* boot checksum sub-regions */ + bh = sb_bread(sb, sn); + if (!bh) + return -EIO; + + for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) { + p_chksum = (u32 *)&bh->b_data[i]; + if (le32_to_cpu(*p_chksum) != chksum) { + exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)", + le32_to_cpu(*p_chksum), chksum); + brelse(bh); + return -EINVAL; + } + } + brelse(bh); + return 0; +} + /* mount the file system volume */ static int __exfat_fill_super(struct super_block *sb) { @@ -498,6 +541,12 @@ static int __exfat_fill_super(struct super_block *sb) goto free_bh; } + ret = exfat_verify_boot_region(sb); + if (ret) { + exfat_err(sb, "invalid boot region"); + goto free_bh; + } + ret = exfat_create_upcase_table(sb); if (ret) { exfat_err(sb, "failed to load upcase table");