{"id":"CVE-2026-89589","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nacpi/apei/ghes: Use raw_spinlock_t for CXL CPER work locks\n\nThe CXL CPER work registration and unregistration helpers acquire\ncxl_cper_work_lock and cxl_cper_prot_err_w…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nacpi/apei/ghes: Use raw_spinlock_t for CXL CPER work locks\n\nThe CXL CPER work registration and unregistration helpers acquire\ncxl_cper_work_lock and cxl_cper_prot_err_w…","severity":"medium","cvss":4.4,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-833"],"vendor":"Linux","product":"Linux","affected":["Linux >= 5e4a264bf8b55d5a1b4c8cd96ac10b99f98d7487 < cbc27a4302a1feb0ff77c1755021837a738b0ce9","Linux >= 5e4a264bf8b55d5a1b4c8cd96ac10b99f98d7487 < c735dbce7ad03df708bf22ec964f67e43cbc823a","Linux >= 5e4a264bf8b55d5a1b4c8cd96ac10b99f98d7487 < 0e25382b05de48d09b243d3d447d236a6d735bc2","Linux >= 5e4a264bf8b55d5a1b4c8cd96ac10b99f98d7487 < 6625ca499c3131ef63be3215f8f942d7a097ea3a","Linux 6.10"],"published":"2026-09-11","updated":"2026-09-21","sourceUpdated":"2026-09-21T14:17:23.690","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-89589","references":[{"url":"https://git.kernel.org/stable/c/0e25382b05de48d09b243d3d447d236a6d735bc2","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6625ca499c3131ef63be3215f8f942d7a097ea3a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c735dbce7ad03df708bf22ec964f67e43cbc823a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cbc27a4302a1feb0ff77c1755021837a738b0ce9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89589.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89589"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532404"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89589"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89589"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89589.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00175,"epssPercentile":0.07294,"cvssSource":"vendor","ingestedAt":"2026-09-14T11:11:19.886Z","slug":"CVE-2026-89589","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nacpi/apei/ghes: Use raw_spinlock_t for CXL CPER work locks\n\nThe CXL CPER work registration and unregistration helpers acquire\ncxl_cper_work_lock and cxl_cper_prot_err_work_lock with a spinlock\nguard(), which leaves local interrupts enabled. The corresponding post\npaths (cxl_cper_post_event(), cxl_cper_post_prot_err()) execute in hard\nIRQ context (they are called from the GHES error notification path) and\nacquire the same locks with an irqsave guard().\n\nIf a CPU is holding one of these locks via a spinlock guard() when a GHES\ninterrupt arrives on the same CPU, the IRQ handler spins on the held lock\nwaiting for it to release, while the lock holder is preempted by the IRQ.\nThe result is a deadlock.\n\nConvert both locks from spinlock_t to raw_spinlock_t and use guard() at\nall call sites. On PREEMPT_RT kernels spinlock_t is backed by rt_mutex and\nsleeping from hard IRQ context is not permitted; raw_spinlock_t is safe in\nboth contexts.\n\nAdd WARN_ONCE to both register functions to surface double-registration\nbugs at runtime.\n\nRestructure both unregister functions to clear the global work pointer\nunder the lock before calling cancel_work_sync(), closing the window\nwhere a CPER interrupt could schedule work on a pointer about to be\nfreed. Add kfifo_reset() after cancel_work_sync() so stale entries\nare not replayed on next module load.\n\nBoth kfifos are single-consumer: only one work_struct is registered at\na time, enforced by the WARN_ONCE guard in the register functions.\nkfifo_reset() is safe outside the lock because cancel_work_sync() has\nalready quiesced the consumer, and no new consumer can register until\nthe current module exit completes and a fresh module init runs.\n\nRemove the redundant cancel_work_sync() call from cxl_ras_exit() and\ncxl_pci_driver_exit(). The CPER unregister functions now quiesce\nthe work internally.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89589.json)","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":24.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":203961,"id":"CVE-2026-89589","ts":1789490230810,"field":"cvss","old":null,"new":"4.4"},{"seq":203960,"id":"CVE-2026-89589","ts":1789490230810,"field":"severity","old":"none","new":"medium"},{"seq":147215,"id":"CVE-2026-89589","ts":1789270201842,"field":"cvss","old":null,"new":"4.4"},{"seq":147214,"id":"CVE-2026-89589","ts":1789270201842,"field":"severity","old":"none","new":"medium"},{"seq":108970,"id":"CVE-2026-89589","ts":1789183729782,"field":"cvss","old":null,"new":"4.4"},{"seq":108969,"id":"CVE-2026-89589","ts":1789183729782,"field":"severity","old":"none","new":"medium"}]}