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 i…

Overview

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().

Affected

• linux_kernel >= 4.19, < 5.10.261
• linux_kernel >= 5.11, < 5.15.212
• linux_kernel >= 5.16, < 6.1.178
• linux_kernel >= 6.2, < 6.6.145
• linux_kernel >= 6.7, < 6.12.96
• linux_kernel >= 6.13, < 6.18.39
• linux_kernel >= 6.19, < 7.1.4
• linux_kernel = 7.2

Remediation

Upgrade past the affected range:

• linux_kernel 7.1.4