From patchwork Mon Dec 9 11:10:57 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Russell King (Oracle)" X-Patchwork-Id: 11279175 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 5320F6C1 for ; Mon, 9 Dec 2019 11:11:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3206A207FF for ; Mon, 9 Dec 2019 11:11:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="LxwUJX5g" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727755AbfLILLB (ORCPT ); Mon, 9 Dec 2019 06:11:01 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:60184 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727566AbfLILLB (ORCPT ); Mon, 9 Dec 2019 06:11:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Date:Sender:Message-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:Subject:Cc:To:From:References: In-Reply-To:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=5KvYw86H8ov56Iw2bI9SEfpL4gdug7aRu06X5Br42h4=; b=LxwUJX5g63E7wK/STNqftvXICy +AhYPSbyecCuCMXnr0uFHNB2lbT6hfF85rP8JRslV82tRO15YVtan85RppsjEMVNDdRCqrWlxAmyx ehN6+/QpYIhaZwtSSDsT5y0YTOgWFt7uevIa16XQPTi5Em/KsGIevLc09IIX20qu7RemLECJOKxTD NRBs3av9wBnRVteeEw4QfkWYockQd9kMOI+eJD1tK4iScFk7lPryNp1weSgFyKQZ+QOiVWHgNbm8v CJwEeKsOZ6S62vXSvvfp6Zhasu0EtDgsfX8P2jrVkiDZXQFlbbIdDn06hGFAsLc1f7c8QsGfyeurP ktORyq8g==; Received: from e0022681537dd.dyn.armlinux.org.uk ([fd8f:7570:feb6:1:222:68ff:fe15:37dd]:54102 helo=rmk-PC.armlinux.org.uk) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ieGwM-0002X2-Av; Mon, 09 Dec 2019 11:10:58 +0000 Received: from rmk by rmk-PC.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1ieGwL-0004dV-Qg; Mon, 09 Dec 2019 11:10:57 +0000 In-Reply-To: <20191209110731.GD25745@shell.armlinux.org.uk> References: <20191209110731.GD25745@shell.armlinux.org.uk> From: Russell King To: Al Viro Cc: linux-fsdevel@vger.kernel.org Subject: [PATCH 32/41] fs/adfs: bigdir: extract directory validation MIME-Version: 1.0 Content-Disposition: inline Message-Id: Date: Mon, 09 Dec 2019 11:10:57 +0000 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Extract the directory validation from the directory reading function as we will want to re-use this code. Signed-off-by: Russell King --- fs/adfs/dir_fplus.c | 41 +++++++++++++++++++++++++++++++---------- 1 file changed, 31 insertions(+), 10 deletions(-) diff --git a/fs/adfs/dir_fplus.c b/fs/adfs/dir_fplus.c index 393921f5121e..b83a74e9ff6d 100644 --- a/fs/adfs/dir_fplus.c +++ b/fs/adfs/dir_fplus.c @@ -16,6 +16,30 @@ static unsigned int adfs_fplus_offset(const struct adfs_bigdirheader *h, pos * sizeof(struct adfs_bigdirentry); } +static int adfs_fplus_validate_header(const struct adfs_bigdirheader *h) +{ + unsigned int size = le32_to_cpu(h->bigdirsize); + + if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 || + h->bigdirversion[2] != 0 || + h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME) || + size & 2047) + return -EIO; + + return 0; +} + +static int adfs_fplus_validate_tail(const struct adfs_bigdirheader *h, + const struct adfs_bigdirtail *t) +{ + if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) || + t->bigdirendmasseq != h->startmasseq || + t->reserved[0] != 0 || t->reserved[1] != 0) + return -EIO; + + return 0; +} + static int adfs_fplus_read(struct super_block *sb, u32 indaddr, unsigned int size, struct adfs_dir *dir) { @@ -30,6 +54,11 @@ static int adfs_fplus_read(struct super_block *sb, u32 indaddr, return ret; dir->bighead = h = (void *)dir->bhs[0]->b_data; + if (adfs_fplus_validate_header(h)) { + adfs_error(sb, "dir %06x has malformed header", indaddr); + goto out; + } + dirsize = le32_to_cpu(h->bigdirsize); if (dirsize != size) { adfs_msg(sb, KERN_WARNING, @@ -37,13 +66,6 @@ static int adfs_fplus_read(struct super_block *sb, u32 indaddr, indaddr, dirsize, size); } - if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 || - h->bigdirversion[2] != 0 || size & 2047 || - h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME)) { - adfs_error(sb, "dir %06x has malformed header", indaddr); - goto out; - } - /* Read remaining buffers */ ret = adfs_dir_read_buffers(sb, indaddr, dirsize, dir); if (ret) @@ -52,9 +74,8 @@ static int adfs_fplus_read(struct super_block *sb, u32 indaddr, dir->bigtail = t = (struct adfs_bigdirtail *) (dir->bhs[dir->nr_buffers - 1]->b_data + (sb->s_blocksize - 8)); - if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) || - t->bigdirendmasseq != h->startmasseq || - t->reserved[0] != 0 || t->reserved[1] != 0) { + ret = adfs_fplus_validate_tail(h, t); + if (ret) { adfs_error(sb, "dir %06x has malformed tail", indaddr); goto out; }