Description
In the Linux kernel, the following vulnerability has been resolved: ntfs: reject invalid sectors_per_cluster in the boot sector is_boot_sector_ntfs() checks the boot sector's sectors_per_cluster field with a range test that rejects 0x81..0xf3 but accepts 0 and other non-power-of-two counts. A zero value reaches parse_ntfs_boot_sector(): sectors_per_cluster_bits = ffs(sectors_per_cluster) - 1; ... vol->cluster_size = vol->sector_size << sectors_per_cluster_bits; ffs(0) is 0, so sectors_per_cluster_bits becomes (unsigned)-1 and the shift is undefined: UBSAN: shift-out-of-bounds in fs/ntfs/super.c:673:39 shift exponent 4294967295 is too large for 32-bit type 'int' This change rejects any non-power-of-two value, since it feeds the aforementioned shift via ffs() - 1, which only yields the correct shift for a power of two.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
6251f0b0de7d645e3591931ca4c11d8322c1866f to < 7524c3145a3bac92bebbc47a29c007f1d874c9b3affected6251f0b0de7d645e3591931ca4c11d8322c1866f to < 323751a604e7533fa473874d999371592a614207affected
Linux Linux
Default version status: affected
7.1affected0 to < 7.1unaffected7.2.7 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected