CVE-2026-89622

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

State: Published
Severity: 7.8 High
Published: Sep 11, 2026
Updated: Oct 30, 2026
Reserved: Sep 11, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	67a95c21463d066060b0f66d65a75d45bb386ffb to before 198bf4a226229e36dfe254493a45c71c3ffc7e57Affected 67a95c21463d066060b0f66d65a75d45bb386ffb to before bd146a8ff107c6d77e75597decbcd1df0d7900d6Affected 67a95c21463d066060b0f66d65a75d45bb386ffb to before d6c6b293173c0ea87189501cbd77e8fa677814a1Affected 67a95c21463d066060b0f66d65a75d45bb386ffb to before 03c34309eb1bce1b3b5f7c4a94b703f419120383Affected 67a95c21463d066060b0f66d65a75d45bb386ffb to before 968546b676d992dd1da3e057d40598231f725996Affected 67a95c21463d066060b0f66d65a75d45bb386ffb to before db2333f88729c8aae062cb171ed058725ff5c901Affected
LinuxLinux	5.7Affected before 5.7Not affected 6.1.191 through 6.1.Not affected 6.6.160 through 6.6.Not affected 6.12.111 through 6.12.Not affected 6.18.51 through 6.18.Not affected 7.2.4 through 7.2.*Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

67a95c21463d066060b0f66d65a75d45bb386ffb to before 198bf4a226229e36dfe254493a45c71c3ffc7e57Affected
67a95c21463d066060b0f66d65a75d45bb386ffb to before bd146a8ff107c6d77e75597decbcd1df0d7900d6Affected
67a95c21463d066060b0f66d65a75d45bb386ffb to before d6c6b293173c0ea87189501cbd77e8fa677814a1Affected
67a95c21463d066060b0f66d65a75d45bb386ffb to before 03c34309eb1bce1b3b5f7c4a94b703f419120383Affected
67a95c21463d066060b0f66d65a75d45bb386ffb to before 968546b676d992dd1da3e057d40598231f725996Affected
67a95c21463d066060b0f66d65a75d45bb386ffb to before db2333f88729c8aae062cb171ed058725ff5c901Affected

LinuxLinux

5.7Affected
before 5.7Not affected
6.1.191 through 6.1.*Not affected
6.6.160 through 6.6.*Not affected
6.12.111 through 6.12.*Not affected
6.18.51 through 6.18.*Not affected
7.2.4 through 7.2.*Not affected
7.3 and laterNot affected

References

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