Use after free in Linux kernel mtk-sd MMC driver on remove
Key facts
- Attack vector
- —
- Privileges required
- —
- User interaction
- —
- Attack complexity
- —
- Impact type
- —
- Confidentiality · integrity · availability
- —
- Fix status
- Partial Red Hat: 2 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel mtk-sd MMC host driver does not wait for a request timeout callback that has already started before it releases host resources during removal. The callback can keep using the host after it is freed, which causes a use-after-free. The flaw is present from Linux kernel 4.2 until the fixed releases.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: mmc: mtk-sd: Cancel request timeout work on remove The driver queues req_timeout while a request is active. msdc_request_done() uses cancel_delayed_work(), which does not wait for a timeout callback that has already started. The timeout callback calls mmc_request_done(), which wakes the request waiter, and then continues to use host->dev_comp and check the SDIO IRQ. During unbind, msdc_drv_remove() can return and the managed mmc_host can be freed before the callback finishes. KASAN reported use-after-free accesses in msdc_request_done() and msdc_recheck_sdio_irq() in each of three unbind tests. The same tests completed without a kernel diagnostic after this change. Call cancel_delayed_work_sync() after mmc_remove_host() has stopped new requests and before the driver releases the host resources.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Update the Linux kernel to 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.57, 7.2.11 or 7.3, matching the release branch in use. Red Hat lists Red Hat Enterprise Linux 8 and Red Hat OpenShift Container Platform 4 as affected with no available fix plan.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.57, 7.2.11, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
Not affected: 6 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-23 Threatist record created from CVE-2026-99035
- 2026-10-23 Alias added: GHSA-pwxj-3q2q-r972
- 2026-10-29 Affected versions changed · Red Hat
- 2026-10-29 CVSS score added · Red Hat
- 2026-10-30 Fix available: Linux/Linux@2cff6a2a912a3464ae1fefb7e0a82393682ccea6, Linux/[email protected], Linux/[email protected] +3 · CNA
- 2026-10-30 3 new references · CNA
- 2026-11-06 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/d8ce81006ee4e42ce2d0bd3a2ab87adc1e24ef11
- https://git.kernel.org/stable/c/2cff6a2a912a3464ae1fefb7e0a82393682ccea6
- https://git.kernel.org/stable/c/e5d82695f2cabca3222b8f6a89ea0e18bafc4c0a
- https://git.kernel.org/stable/c/9e799f25c420e759641eb25102967ea091fc758f
- https://git.kernel.org/stable/c/f37e0367ad6f2147a0b37564b442b7a25bec0d23
- https://git.kernel.org/stable/c/46e75703ca3f00fb8c935b3ce35b90836e34e8af
- https://git.kernel.org/stable/c/edef1355224c0799a502a46b71d3649fa0dd218e
- https://git.kernel.org/stable/c/b38af5386a74416e898955443f2e26547b358cb2
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-2026-99035 · CVE Program
- CVE-2026-99035 · NVD
- FIRST EPSS
- GHSA-pwxj-3q2q-r972 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-99035 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences