CVE-2026-63893

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> thunderbolt: property: Reject u32 wrap in tb_property_entry_valid()<br /> <br /> entry-&gt;value is u32 and entry-&gt;length is u16; the sum is performed in<br /> u32 and wraps. A malicious XDomain peer can pick<br /> value = 0xffffff00, length = 0x100 so the sum 0x100000000 wraps to 0<br /> and passes the &gt; block_len check. tb_property_parse() then passes<br /> entry-&gt;value to parse_dwdata() as a dword offset into the property<br /> block, reading attacker-directed memory far past the allocation.<br /> <br /> For TEXT-typed entries with the "deviceid" or "vendorid" keys this<br /> lands in xd-&gt;device_name / xd-&gt;vendor_name and is readable back via<br /> the per-XDomain device_name / vendor_name sysfs attributes; the leak<br /> is NUL-bounded (kstrdup() stops at the first zero byte) and<br /> untargeted (the attacker picks a delta, not an absolute address).<br /> DATA-typed entries are parsed into property-&gt;value.data but not<br /> generically surfaced to userspace.<br /> <br /> Use check_add_overflow() so a wrapped sum is rejected.