CVE-2026-89622

Summary

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 Software

VendorProductVersion RangeStatus
LinuxLinux67a95c21463d066060b0f66d65a75d45bb386ffb < 03c34309eb1bce1b3b5f7c4a94b703f419120383affected
LinuxLinux67a95c21463d066060b0f66d65a75d45bb386ffb < 968546b676d992dd1da3e057d40598231f725996affected
LinuxLinux67a95c21463d066060b0f66d65a75d45bb386ffb < db2333f88729c8aae062cb171ed058725ff5c901affected
LinuxLinux5.7affected
LinuxLinux0 < 5.7unaffected
LinuxLinux6.18.51 <= 6.18.*unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References