From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= Date: Thu, 10 Nov 2022 18:35:00 +0100 Subject: [PATCH 25/26] libblkid: ntfs: avoid UB in signed shift Fix OSS-Fuzz issue 53142 ( #1886 ) Fix OSS-Fuzz issue 53160 ( #1888 ) --- libblkid/src/superblocks/ntfs.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/libblkid/src/superblocks/ntfs.c b/libblkid/src/superblocks/ntfs.c index dced699..217e7e8 100644 --- a/libblkid/src/superblocks/ntfs.c +++ b/libblkid/src/superblocks/ntfs.c @@ -135,11 +135,15 @@ static int __probe_ntfs(blkid_probe pr, const struct blkid_idmag *mag, int save_ } } - if (ns->clusters_per_mft_record > 0) + if (ns->clusters_per_mft_record > 0) { mft_record_size = ns->clusters_per_mft_record * sectors_per_cluster * sector_size; - else - mft_record_size = 1 << (0 - ns->clusters_per_mft_record); + } else { + int8_t mft_record_size_shift = 0 - ns->clusters_per_mft_record; + if (mft_record_size_shift < 0 || mft_record_size_shift >= 31) + return 1; + mft_record_size = 1 << mft_record_size_shift; + } nr_clusters = le64_to_cpu(ns->number_of_sectors) / sectors_per_cluster;