# CVE-2026-98198: hwmon: (pwm-fan) Stop RPM timer before freeing tach data CVE-2026-98198 is fixed in 37 products on 1 platform, first by DEBIAN-CVE-2026-98198, released October 6, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-98198 - Priority: Routine - CVSS: 5.5 (Moderate) - EPSS: 0.0017 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Oct 6, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-98198 ## Description In the Linux kernel, the following vulnerability has been resolved: hwmon: (pwm-fan) Stop RPM timer before freeing tach data sample_timer() rearms the RPM timer and accesses the devm-managed ctx->tachs and ctx->pulses_per_revolution arrays. The cleanup action which stops the timer is registered before those arrays are allocated. Since devres releases entries in reverse order, driver detach can free the arrays before pwm_fan_cleanup() shuts down the timer. A timer expiry in that window accesses the freed tach data. With a KASAN kernel, a test-only kprobe delayed entry to pwm_fan_cleanup() while normal sysfs unbind ran. Each of three runs reported three four-byte reads and two four-byte writes in sample_timer() after its backing devm allocations had been freed. The helper did not invoke the timer callback, cleanup actions or free functions. With the fix, three matching unbind runs completed without KASAN, BUG, WARNING, Oops or panic. Instrumentation confirmed that timer retirement completed before the first timer backing allocation was released. Split timer retirement from the power cleanup and register its devres action after the timer backing data and IRQ actions are installed. This preserves the early power rollback action while ensuring the timer is retired before its backing data is released. Use timer_shutdown_sync() because the callback can rearm itself. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | kernel-uek ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-devel ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-devel ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-doc ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-doc ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-tools ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-tools ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.113-1 | [DEBIAN-CVE-2026-98198](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98198.md) | Oct 6, 2026 | | Linux | linux Debian 14 | 7.2.8-1 | [DEBIAN-CVE-2026-98198](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98198.md) | Oct 6, 2026 | | Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.113-1~deb12u1 | [DEBIAN-CVE-2026-98198](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98198.md) | Oct 6, 2026 | --- Data as of 2026-11-09T01:18:40Z UTC. 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