CVE-2026-31729 PUBLISHED

usb: typec: ucsi: validate connector number in ucsi_notify_common()

Assigner: Linux
Reserved: 09.03.2026 Published: 01.05.2026 Updated: 01.05.2026

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

usb: typec: ucsi: validate connector number in ucsi_notify_common()

The connector number extracted from CCI via UCSI_CCI_CONNECTOR() is a 7-bit field (0-127) that is used to index into the connector array in ucsi_connector_change(). However, the array is only allocated for the number of connectors reported by the device (typically 2-4 entries).

A malicious or malfunctioning device could report an out-of-range connector number in the CCI, causing an out-of-bounds array access in ucsi_connector_change().

Add a bounds check in ucsi_notify_common(), the central point where CCI is parsed after arriving from hardware, so that bogus connector numbers are rejected before they propagate further.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from bdc62f2bae8fb0e8e99574de5232f0a3c54a27df to f6dcbf2b024d55549959402f1db6c614e51d52cb (excl.)
  • affected from bdc62f2bae8fb0e8e99574de5232f0a3c54a27df to f4e608fe12b7ac6a4a57176ab0296bb5a110a078 (excl.)
  • affected from bdc62f2bae8fb0e8e99574de5232f0a3c54a27df to 98429e9ec89a5e3a204112dfaa2dbe6ca28493a0 (excl.)
  • affected from bdc62f2bae8fb0e8e99574de5232f0a3c54a27df to d2d8c17ac01a1b1f638ea5d340a884ccc5015186 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 5.5 is affected
  • unaffected from 0 to 5.5 (excl.)
  • unaffected from 6.12.81 to 6.12.* (incl.)
  • unaffected from 6.18.22 to 6.18.* (incl.)
  • unaffected from 6.19.12 to 6.19.* (incl.)
  • unaffected from 7.0 to * (incl.)

References