From owner-svn-src-stable-11@freebsd.org Mon Sep 11 08:16:40 2017 Return-Path: Delivered-To: svn-src-stable-11@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 26F34E22372; Mon, 11 Sep 2017 08:16:40 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id E6C0875E5A; Mon, 11 Sep 2017 08:16:39 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v8B8GdVn012613; Mon, 11 Sep 2017 08:16:39 GMT (envelope-from kib@FreeBSD.org) Received: (from kib@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id v8B8GdaX012612; Mon, 11 Sep 2017 08:16:39 GMT (envelope-from kib@FreeBSD.org) Message-Id: <201709110816.v8B8GdaX012612@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kib set sender to kib@FreeBSD.org using -f From: Konstantin Belousov Date: Mon, 11 Sep 2017 08:16:39 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r323429 - stable/11/sys/fs/msdosfs X-SVN-Group: stable-11 X-SVN-Commit-Author: kib X-SVN-Commit-Paths: stable/11/sys/fs/msdosfs X-SVN-Commit-Revision: 323429 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-stable-11@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for only the 11-stable src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 11 Sep 2017 08:16:40 -0000 Author: kib Date: Mon Sep 11 08:16:38 2017 New Revision: 323429 URL: https://svnweb.freebsd.org/changeset/base/323429 Log: MFC r322982: Verify that the BPB media descriptor and FAT ID match. Modified: stable/11/sys/fs/msdosfs/msdosfs_fat.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/fs/msdosfs/msdosfs_fat.c ============================================================================== --- stable/11/sys/fs/msdosfs/msdosfs_fat.c Mon Sep 11 07:38:53 2017 (r323428) +++ stable/11/sys/fs/msdosfs/msdosfs_fat.c Mon Sep 11 08:16:38 2017 (r323429) @@ -908,19 +908,17 @@ fillinusemap(struct msdosfsmount *pmp) * zero. These represent free clusters. */ pmp->pm_freeclustercount = 0; - for (cn = CLUST_FIRST; cn <= pmp->pm_maxcluster; cn++) { + for (cn = 0; cn <= pmp->pm_maxcluster; cn++) { byteoffset = FATOFS(pmp, cn); bo = byteoffset % pmp->pm_fatblocksize; - if (!bo || !bp) { + if (bo == 0) { /* Read new FAT block */ - if (bp) + if (bp != NULL) brelse(bp); fatblock(pmp, byteoffset, &bn, &bsize, NULL); error = bread(pmp->pm_devvp, bn, bsize, NOCRED, &bp); - if (error) { - brelse(bp); + if (error != 0) return (error); - } } if (FAT32(pmp)) readcn = getulong(&bp->b_data[bo]); @@ -930,7 +928,19 @@ fillinusemap(struct msdosfsmount *pmp) readcn >>= 4; readcn &= pmp->pm_fatmask; - if (readcn == CLUST_FREE) + /* + * Check if the FAT ID matches the BPB's media descriptor and + * all other bits are set to 1. + */ + if (cn == 0 && readcn != ((pmp->pm_fatmask & 0xffffff00) | + pmp->pm_bpb.bpbMedia)) { +#ifdef MSDOSFS_DEBUG + printf("mountmsdosfs(): Media descriptor in BPB" + "does not match FAT ID\n"); +#endif + brelse(bp); + return (EINVAL); + } else if (readcn == CLUST_FREE) usemap_free(pmp, cn); } if (bp != NULL)