CVE-2026-63892 thunderbolt: property: Reject dir_len < 4 to prevent size_t underflow

In the Linux kernel, the following vulnerability has been resolved: thunderbolt: property: Reject dirlen length u16 widened to sizet. Two distinct OOB conditions follow when entry-length uuid, ... which always reads 4 dwords from diroffset. tbpropertyentryvalid only enforces diroffset +...

CVE-2026-63892

CVE-2026-63892 affects the Linux kernel thunderbolt property parsing. The non-root path in __tb_property_parse_dir() may read beyond the end of a property block when entry-&gt;length length and the code copies 4 dwords from dir_offset regardless of dir_len. This creates two OOB conditions: (1) a ...