CVEvulnerability
CVE-2026-89622
7.8 HIGH
Official page ↗
- Status
- Received
- Published
- 2026-09-11
- Last modified
- 2026-10-21
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
- 7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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.
References
- https://git.kernel.org/stable/c/03c34309eb1bce1b3b5f7c4a94b703f419120383 git.kernel.org
- https://git.kernel.org/stable/c/968546b676d992dd1da3e057d40598231f725996 git.kernel.org
- https://git.kernel.org/stable/c/bd146a8ff107c6d77e75597decbcd1df0d7900d6 git.kernel.org
- https://git.kernel.org/stable/c/d6c6b293173c0ea87189501cbd77e8fa677814a1 git.kernel.org
- https://git.kernel.org/stable/c/db2333f88729c8aae062cb171ed058725ff5c901 git.kernel.org