{"id":"CVE-2026-89589","summary":"acpi/apei/ghes: Use raw_spinlock_t for CXL CPER work locks","details":"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_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.","modified":"2026-09-13T03:47:19.549982613Z","published":"2026-09-11T19:44:53.578Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89589.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0e25382b05de48d09b243d3d447d236a6d735bc2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6625ca499c3131ef63be3215f8f942d7a097ea3a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c735dbce7ad03df708bf22ec964f67e43cbc823a"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89589.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89589"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5e4a264bf8b55d5a1b4c8cd96ac10b99f98d7487"},{"fixed":"c735dbce7ad03df708bf22ec964f67e43cbc823a"},{"fixed":"0e25382b05de48d09b243d3d447d236a6d735bc2"},{"fixed":"6625ca499c3131ef63be3215f8f942d7a097ea3a"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89589.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.10.0"},{"fixed":"6.18.50"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89589.json"}}],"schema_version":"1.9.0"}