CVE-2026-64330

In the Linux kernel, the following vulnerability has been resolved:

usb: typec: tcpm: Validate SVID index in svdm_consume_modes()

In svdm_consume_modes(), the SVID value is read from pmdata->svids using

pmdata->svid_index as an array index without bounds validation:

paltmode->svid = pmdata->svids[pmdata->svid_index];

If pmdata->svid_index is driven beyond SVID_DISCOVERY_MAX (16), it results

in an out-of-bounds read of the pmdata->svids array. Because pd_mode_data

is embedded inside struct tcpm_port, indexing past svids reads into

adjacent fields. In particular:

- At index 16, it reads the altmodes count.

- At index 18 and beyond, it reads into altmode_desc[], which contains

partner-supplied SVDM Discovery Modes VDOs.

By injecting a chosen SVID into altmode_desc[0].vdo and driving svid_index

to 20, the partner can force paltmode->svid to be loaded with an arbitrary,

partner- chosen SVID, which is then registered via

typec_partner_register_altmode().

Fix this by validating that pmdata->svid_index is non-negative and strictly

less than pmdata->nsvids before accessing the pmdata->svids array inside

svdm_consume_modes().