CVE-2026-89622

HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes

HIGH
7.8
CVSS Score
Published: September 11, 2026 at 07:45 PM UTC
Updated: October 21, 2026 at 01:20 PM UTC
1 product affected across 1 vendorLinux Kernel

Using Linux by Linux?

Get instant alerts when new vulnerabilities affect Linux - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.8
Exploit prediction
EPSS 0.2%

Description

In the Linux kernel, the following vulnerability has been resolved: HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes mcp_i2c_smbus_read() stores the caller-supplied buffer pointer in mcp->rxbuf for the duration of a transfer but never clears it when the transfer finishes or times out. Once the caller frees or reuses the buffer, mcp->rxbuf becomes a dangling pointer. A delayed or spurious MCP2221_I2C_GET_DATA report can then drive mcp2221_raw_event() to memcpy device data into the freed memory, causing a write use-after-free. Route all return paths through a single exit point that clears mcp->rxbuf and mcp->rxbuf_size, so that the existing !mcp->rxbuf guard in the raw_event handler can reject any report arriving after the transfer has ended.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.767a95c21463d066060b0f66d65a75d45bb386ffb
Vendor states this is fixed in 03c34309eb1bce1b3b5f7c4a94b703f419120383 (fixed)
Vendor states this is fixed in 968546b676d992dd1da3e057d40598231f725996 (fixed)
Vendor states this is fixed in d6c6b293173c0ea87189501cbd77e8fa677814a1 (fixed)
Vendor states this is fixed in db2333f88729c8aae062cb171ed058725ff5c901 (fixed)
Vendor states this is fixed in 5.7 (unaffected)
Vendor states this is fixed in 6.12.111 (unaffected)
Vendor states this is fixed in 6.18.51 (unaffected)
Vendor states this is fixed in 6.6.160 (unaffected)
Vendor states this is fixed in 7.2.4 (unaffected)
Vendor states this is fixed in 7.3 (unaffected)
Vendor states this is fixed in 7.3-rc1 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

CVSS

7.8HIGHLinux
Vector?

Quick Info

StatusRECEIVED

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card