CVE-2026-64323

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> udf: validate VAT header length against the VAT inode size<br /> <br /> udf_load_vat() takes the virtual partition&amp;#39;s start offset straight from<br /> the on-disk VAT 2.0 header without checking it against the VAT inode<br /> size:<br /> <br /> map-&gt;s_type_specific.s_virtual.s_start_offset =<br /> le16_to_cpu(vat20-&gt;lengthHeader);<br /> map-&gt;s_type_specific.s_virtual.s_num_entries =<br /> (sbi-&gt;s_vat_inode-&gt;i_size -<br /> map-&gt;s_type_specific.s_virtual.s_start_offset) &gt;&gt; 2;<br /> <br /> lengthHeader is a fully attacker-controlled 16-bit value. If it exceeds<br /> the VAT inode size, the s_num_entries subtraction underflows to a huge<br /> count, which defeats the "block &gt; s_num_entries" bound in<br /> udf_get_pblock_virt15(); and on the ICB-inline path that function reads<br /> <br /> ((__le32 *)(iinfo-&gt;i_data + s_start_offset))[block]<br /> <br /> so a large s_start_offset indexes past the inode&amp;#39;s in-ICB data. Mounting<br /> a crafted UDF image with a virtual (VAT) partition then triggers an<br /> out-of-bounds read.<br /> <br /> Reject a VAT whose header length does not leave room for at least one<br /> entry within the VAT inode.