Author: delphij Date: Thu Jul 12 05:37:52 2018 New Revision: 336218 URL: https://svnweb.freebsd.org/changeset/base/336218
Log: MFC r335696,r335697: Detect exFAT filesystems and abort if found and tighten BPB sanity check. Obtained from: Android https://android-review.googlesource.com/61827 Modified: stable/11/sbin/fsck_msdosfs/boot.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sbin/fsck_msdosfs/boot.c ============================================================================== --- stable/11/sbin/fsck_msdosfs/boot.c Thu Jul 12 02:51:50 2018 (r336217) +++ stable/11/sbin/fsck_msdosfs/boot.c Thu Jul 12 05:37:52 2018 (r336218) @@ -82,6 +82,11 @@ readboot(int dosfs, struct bootblock *boot) boot->FATsecs = boot->bpbFATsmall; + if (boot->bpbBytesPerSec % DOSBOOTBLOCKSIZE_REAL != 0 || + boot->bpbBytesPerSec / DOSBOOTBLOCKSIZE_REAL == 0) { + pfatal("Invalid sector size: %u", boot->bpbBytesPerSec); + return FSFATAL; + } if (!boot->bpbRootDirEnts) boot->flags |= FAT32; if (boot->flags & FAT32) { @@ -102,6 +107,22 @@ readboot(int dosfs, struct bootblock *boot) boot->bpbFSInfo = block[48] + (block[49] << 8); boot->bpbBackup = block[50] + (block[51] << 8); + /* If the OEM Name field is EXFAT, it's not FAT32, so bail */ + if (!memcmp(&block[3], "EXFAT ", 8)) { + pfatal("exFAT filesystem is not supported."); + return FSFATAL; + } + + /* check basic parameters */ + if ((boot->bpbFSInfo == 0) || (boot->bpbSecPerClust == 0)) { + /* + * Either the BIOS Parameter Block has been corrupted, + * or this is not a FAT32 filesystem, most likely an + * exFAT filesystem. + */ + pfatal("Invalid FAT32 Extended BIOS Parameter Block"); + return FSFATAL; + } if (lseek(dosfs, boot->bpbFSInfo * boot->bpbBytesPerSec, SEEK_SET) != boot->bpbFSInfo * boot->bpbBytesPerSec || read(dosfs, fsinfo, sizeof fsinfo) != sizeof fsinfo) { @@ -178,11 +199,6 @@ readboot(int dosfs, struct bootblock *boot) /* Check backup bpbFSInfo? XXX */ } - if (boot->bpbBytesPerSec % DOSBOOTBLOCKSIZE_REAL != 0 || - boot->bpbBytesPerSec == 0) { - pfatal("Invalid sector size: %u", boot->bpbBytesPerSec); - return FSFATAL; - } if (boot->bpbSecPerClust == 0) { pfatal("Invalid cluster size: %u", boot->bpbSecPerClust); return FSFATAL; _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
