CVE-2026-64323

In the Linux kernel, the following vulnerability has been resolved: udf: validate VAT header length against the VAT inode size udf_load_vat() takes the virtual partition's start offset straight from the on-disk VAT 2.0 header without checking it against the VAT inode size: map->s_type_specific.s_virtual.s_start_offset = le16_to_cpu(vat20->lengthHeader); map->s_type_specific.s_virtual.s_num_entries = (sbi->s_vat_inode->i_size - map->s_type_specific.s_virtual.s_start_offset) >> 2; lengthHeader is a fully attacker-controlled 16-bit value. If it exceeds the VAT inode size, the s_num_entries subtraction underflows to a huge count, which defeats the "block > s_num_entries" bound in udf_get_pblock_virt15(); and on the ICB-inline path that function reads ((__le32 *)(iinfo->i_data + s_start_offset))[block] so a large s_start_offset indexes past the inode's in-ICB data. Mounting a crafted UDF image with a virtual (VAT) partition then triggers an out-of-bounds read. Reject a VAT whose header length does not leave room for at least one entry within the VAT inode.

• linux linux kernel (>= 2.6.26 < 5.10.261) • linux linux kernel (>= 5.11 < 5.15.212) • linux linux kernel (>= 5.16 < 6.1.178) • linux linux kernel (>= 6.2 < 6.6.145) • linux linux kernel (>= 6.7 < 6.12.96) • linux linux kernel (>= 6.13 < 6.18.39) • linux linux kernel (>= 6.19 < 7.1.4)