{"cve":"CVE-2026-89955","nvd":{"published":"2026-09-16T11:17:05.797","modified":"2026-10-19T09:18:41.583","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio-ap: Fix NULL deref in status_show() during queue probe\n\nWhen vfio_ap_mdev_probe_queue() creates the sysfs attribute group,\nthe queue's driver data has not yet been set. A concurrent read of\nthe 'status' attribute can therefore call dev_get_drvdata() and\nget NULL, which is then passed directly to\nvfio_ap_mdev_for_queue() where q->apqn is unconditionally\ndereferenced, causing a NULL pointer dereference.\n\nFix this by acquiring the update locks before calling\nsysfs_create_group(). The status_show() function acquires\nguests_lock before reading the driver data, so any concurrent\nread will block until after dev_set_drvdata() has been called\nand the update locks are released.\n\nAs a bonus, the APQN no longer needs to be read from the queue\nstruct after allocation — it can be read directly from apdev\nbefore allocation and stored in a local variable, which is then\nassigned to q->apqn once the allocation succeeds.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/31fa0a8a3c337ed2d200166d6926ab23c14f8b2e","https://git.kernel.org/stable/c/69632952aca04caa71e49953b6949fc04e788e67","https://git.kernel.org/stable/c/7db2511fc601ca3a6e3fb1bdce02261c3c3167c3","https://git.kernel.org/stable/c/dd6f4ef6f8a37412909ad787c837332fb070159c","https://git.kernel.org/stable/c/e102ce0f4af99dff769a4b1b4daa4cc6bd5ad2d9"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:54:41.405518556+00:00"},"epss":{"cve":"CVE-2026-89955","score":0.002,"percentile":0.09719,"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."]}