HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.111, 6.18.51, 7.2.4, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 7 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-89622
- 2026-10-03 Alias added: GHSA-hmph-x79p-jwjq
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-21 Fix available: Linux/[email protected], Linux/Linux@bd146a8ff107c6d77e75597decbcd1df0d7900d6 · CNA
- 2026-10-21 1 new reference · CNA
- 2026-10-30 Fix available: Linux/Linux@198bf4a226229e36dfe254493a45c71c3ffc7e57, Linux/[email protected] · CNA
- 2026-10-30 1 new reference · CNA
- 2026-10-30 Affected versions changed · Red Hat
References
Other 6
- https://git.kernel.org/stable/c/198bf4a226229e36dfe254493a45c71c3ffc7e57
- https://git.kernel.org/stable/c/bd146a8ff107c6d77e75597decbcd1df0d7900d6
- https://git.kernel.org/stable/c/d6c6b293173c0ea87189501cbd77e8fa677814a1
- https://git.kernel.org/stable/c/03c34309eb1bce1b3b5f7c4a94b703f419120383
- https://git.kernel.org/stable/c/968546b676d992dd1da3e057d40598231f725996
- https://git.kernel.org/stable/c/db2333f88729c8aae062cb171ed058725ff5c901
More Linux vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-89622 · CVE Program
- CVE-2026-89622 · NVD
- FIRST EPSS
- GHSA-hmph-x79p-jwjq · GitHub Advisory Database · CC BY 4.0
- CVE-2026-89622 · Red Hat security data · CC BY 4.0
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