{"cve":"CVE-2026-80916","nvd":{"published":"2026-09-09T17:17:46.513","modified":"2026-10-19T09:17:22.417","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nkcov: fix data corruption and race conditions on PREEMPT_RT\n\nsyzbot is reporting KCOV state corruption on PREEMPT_RT kernels, for the\ntemporary storage used for saving/restoring remote KCOV state is currently\nallocated as the per-CPU area.\n\nOn PREEMPT_RT kernels, softirq handlers run as preemptible task threads\n(e.g., ksoftirqd). If a softirq context preempts a task running a remote\nKCOV session, it safely saves the task's state into the per-CPU area.\nHowever, if that softirq thread is subsequently preempted by a higher-\npriority softirq thread on the same CPU, the second softirq will overwrite\nthe same per-CPU area, permanently destroying the original task's KCOV\nstate.\n\nFix this data corruption by moving the temporary storage from the per-CPU\narea to the per-thread area. Since each softirq thread now owns its own\ntask context, nested softirq preemption no longer causes data overwrites.\n\nNote that while the temporary storage is now on a per-thread basis, the\nper-CPU kcov_percpu_data.lock must be retained, for we need to ensure that\nkcov_remote_start() and kcov_remote_stop() operate atomically without\nracing against asynchronous interrupts that manipulate the current task's\nKCOV state.\n\nIt is likely that GFP_KERNEL allocation by vmalloc_node() in kcov_init()\nhas already called panic() before returning NULL, for there will be no\nOOM-killable userspace processes when __init function of built-in module\nruns. But this patch also fixes crashing the kernel when vmalloc_node()\nin kcov_init() returned NULL, for kcov_init() left per-CPU irq_area == NULL\nbut kcov_remote_start() depends on per-CPU irq_area != NULL, resulting in\n\n  (1) doing vmalloc() in kcov_remote_start() despite !in_task() context\n\n  (2) out-of-array-bounds access if (1) succeeded but\n      kcov->remote_size < CONFIG_KCOV_IRQ_AREA_SIZE\n\n  (3) always leak memory allocated by (1), eventually killing all\n      OOM-killable userspace processes\n\nproblems.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/18799e858b407bf355383c9dd6c06477aa437134","https://git.kernel.org/stable/c/22670d1552fe155822b2abf91f920925f7d067b4","https://git.kernel.org/stable/c/2eed77fdcb0cc48e8eccb2bcd4b7f2c6d650e84c","https://git.kernel.org/stable/c/5dc59fc959b2b5742985d7ef24bccd1868217dc2","https://git.kernel.org/stable/c/8ed3ddf23d39bf5338406bd9f8863d44748cf6ce"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:52:53.108888569+00:00"},"epss":{"cve":"CVE-2026-80916","score":0.00182,"percentile":0.07702,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}