Bug 2521399 (CVE-2026-74585) - CVE-2026-74585 kernel: thunderbolt: Bound the DROM dual link port number before indexing sw->ports
Summary: CVE-2026-74585 kernel: thunderbolt: Bound the DROM dual link port number befo...
Keywords:
Status: NEW
Alias: CVE-2026-74585
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-22 15:43 UTC by OSIDB Bzimport
Modified: 2026-08-24 11:08 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2026-08-22 15:43:38 UTC
In the Linux kernel, the following vulnerability has been resolved:

thunderbolt: Bound the DROM dual link port number before indexing sw->ports

tb_drom_parse_entry_port() validates the device-supplied header->index
against sw->config.max_port_number before indexing sw->ports[], but the
sibling field entry->dual_link_port_nr -- a 6-bit value also read from
the DROM -- indexes the same array with no such check. A malicious or
malformed Thunderbolt device can set dual_link_port_nr beyond the
allocated sw->ports[] (max_port_number + 1 entries), producing an
out-of-bounds tb_port pointer that is stored and later dereferenced.

Reject a port entry whose dual_link_port_nr exceeds max_port_number,
the same bound already applied to header->index.

Comment 1 Mauro Matteo Cascella 2026-08-24 11:04:06 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026082209-CVE-2026-74585-8fe6@gregkh/T


Note You need to log in before you can comment on or make changes to this bug.