CVE-2026-89621

Summary

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

HID: mcp2221: validate report size in mcp2221_raw_event()

mcp2221_raw_event() never validates the size of incoming HID reports. In the MCP2221_I2C_GET_DATA path it trusts the device-supplied data[3] as the copy length without checking that 4 + data[3] bytes actually exist in the received report. A malicious or misbehaving USB device can send a short report with a large data[3], causing the memcpy to read past the valid report data in the HID transfer buffer and leak uninitialized kernel memory back to userspace through the I2C/SMBus read path.

Add a minimum size check at entry and validate that the source range fits within the received report before the copy.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux67a95c21463d066060b0f66d65a75d45bb386ffb < bdc6a3af0dd734a326acdb7d6401a3b6a9f4f149affected
LinuxLinux67a95c21463d066060b0f66d65a75d45bb386ffb < 127de5919820f88a9d55e8371ad4ac49f625f4c5affected
LinuxLinux67a95c21463d066060b0f66d65a75d45bb386ffb < 7c18fb36708a97ff6772825cc087b6d537bbf0d5affected
LinuxLinux67a95c21463d066060b0f66d65a75d45bb386ffb < 2c9a6998c19503626c57a2267bf279e204113079affected
LinuxLinux5.7affected
LinuxLinux0 < 5.7unaffected
LinuxLinux6.12.109 <= 6.12.*unaffected
LinuxLinux6.18.50 <= 6.18.*unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References