From: Thomas Weißschuh Date: Thu, 10 Nov 2022 17:35:00 +0000 (+0100) Subject: libblkid: ntfs: avoid UB in signed shift X-Git-Tag: v2.39-rc1~424^2~1 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9c82a8ca123a4e4028d51f4e38c7c3cfbdc74711;p=thirdparty%2Futil-linux.git libblkid: ntfs: avoid UB in signed shift Fix OSS-Fuzz issue 53142 ( #1886 ) Fix OSS-Fuzz issue 53160 ( #1888 ) --- diff --git a/libblkid/src/superblocks/ntfs.c b/libblkid/src/superblocks/ntfs.c index b5799c3e33..1c53fd29d8 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; diff --git a/tests/ts/fuzzers/test_blkid_fuzz_files/oss-fuzz-53142 b/tests/ts/fuzzers/test_blkid_fuzz_files/oss-fuzz-53142 new file mode 100644 index 0000000000..b671bcd89f Binary files /dev/null and b/tests/ts/fuzzers/test_blkid_fuzz_files/oss-fuzz-53142 differ diff --git a/tests/ts/fuzzers/test_blkid_fuzz_files/oss-fuzz-53160 b/tests/ts/fuzzers/test_blkid_fuzz_files/oss-fuzz-53160 new file mode 100644 index 0000000000..b3586ec748 Binary files /dev/null and b/tests/ts/fuzzers/test_blkid_fuzz_files/oss-fuzz-53160 differ