CVE-2026-89622
Public on 2026-09-11
Modified on 2026-09-15
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.
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.
Severity
See what this means
CVSS v3 Base Score
See breakdown
Affected Packages
| Platform | Package | Release Date | Advisory | Status |
|---|---|---|---|---|
| Amazon Linux 2 - Core | kernel | Not Affected | ||
| Amazon Linux 2 - Kernel-5.10 Extra | kernel | Not Affected | ||
| Amazon Linux 2 - Kernel-5.15 Extra | kernel | Not Affected | ||
| Amazon Linux 2 - Kernel-5.4 Extra | kernel | Not Affected | ||
| Amazon Linux 2023 | kernel | Not Affected | ||
| Amazon Linux 2023 | kernel6.12 | Not Affected | ||
| Amazon Linux 2023 | kernel6.18 | Not Affected |
CVSS Scores
| Score Type | Score | Vector | |
|---|---|---|---|
| Amazon Linux | CVSSv3 | 7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |