From 170181399a026ca44aea0840b498dcff8a931b73 Mon Sep 17 00:00:00 2001 From: Sven Hoexter Date: Thu, 5 Nov 2015 19:59:53 +0100 Subject: [PATCH] Add the fix for https://github.com/relan/exfat/issues/5 found and reported by The Fuzzing Project. Check sector and cluster size. --- debian/changelog | 7 +++++++ libexfat/mount.c | 27 +++++++++++++++++---------- 2 files changed, 24 insertions(+), 10 deletions(-) diff --git a/debian/changelog b/debian/changelog index 5949e25..b3b2dde 100644 --- a/debian/changelog +++ b/debian/changelog @@ -1,3 +1,10 @@ +fuse-exfat (1.1.0-2+deb8u1) UNRELEASED; urgency=medium + + * Add the fix for https://github.com/relan/exfat/issues/5 found + and reported by The Fuzzing Project. Check sector and cluster size. + + -- + fuse-exfat (1.1.0-2) unstable; urgency=low * Remove debian/watch - recent changes at Google code required diff --git a/libexfat/mount.c b/libexfat/mount.c index 2ebf436..2456187 100644 --- a/libexfat/mount.c +++ b/libexfat/mount.c @@ -208,6 +208,23 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options) exfat_error("exFAT file system is not found"); return -EIO; } + /* sector cannot be smaller than 512 bytes */ + if (ef->sb->sector_bits < 9) + { + exfat_close(ef->dev); + exfat_error("too small sector size: 2^%hhd", ef->sb->sector_bits); + free(ef->sb); + return -EIO; + } + /* officially exFAT supports cluster size up to 32 MB */ + if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25) + { + exfat_close(ef->dev); + exfat_error("too big cluster size: 2^(%hhd+%hhd)", + ef->sb->sector_bits, ef->sb->spc_bits); + free(ef->sb); + return -EIO; + } ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb)); if (ef->zero_cluster == NULL) { @@ -242,16 +259,6 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options) free(ef->sb); return -EIO; } - /* officially exFAT supports cluster size up to 32 MB */ - if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25) - { - free(ef->zero_cluster); - exfat_close(ef->dev); - exfat_error("too big cluster size: 2^%d", - (int) ef->sb->sector_bits + (int) ef->sb->spc_bits); - free(ef->sb); - return -EIO; - } if (le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb) > exfat_get_size(ef->dev)) { -- 2.39.5