UBUNTU-CVE-2026-93190: High severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: platform/chrome: crosectypec: Reject out-of-bounds PD cap count crostypecregisterpartnerpdos() copies the partner PDOs from the EC TYPECSTATUS response into the fixed capsdesc.pdo[PDOMAXOBJECTS] array. memcpy(capsdesc.pdo, resp->sourcecappdos, sizeof(u32) resp->sourcecapcount); ... memcpy(capsdesc.pdo, resp->sinkcappdos, sizeof(u32) resp->sinkcapcount); PDOMAXOBJECTS is 7. sourcecapcount and sinkcapcount are u8 fields from the EC. The only check is that they are not both zero. If either is larger than 7, the memcpy writes past the end of the array on the stack. A count of 255 overflows it by about 1 KB. The EC source arrays are only seven entries wide. A larger count reads past them too. The ChromeOS EC firmware caps these counts today, so a compliant setup does not hit this. The kernel should still validate these values rather than trust them. Validate the counts in crostypecregisterpartnerpdos() next to the memcpy. Skip the PDO registration if either count is above PDOMAXOBJECTS. The rest of crostypechandlestatus() still runs so events are handled and cleared.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
In cros_typec_register_partner_pdos(), validate source_cap_count and sink_cap_count before the memcpy operations and skip PDO registration if either count exceeds PDO_MAX_OBJECTS (7); allow the rest of cros_typec_handle_status() to continue running so events are handled and cleared.