CVE-2026-64323
⚠️ highSummary
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; len
Description
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.
📊 Relative Risk Intelligence
This CVE is Moderate Risk - more severe than 52.9% of all 340,405 vulnerabilities in our database.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H