{"id":"CVE-2026-89955","title":"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…","summary":"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…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 260f3ea141382386e97611e7c2029bc013088ab1 < 31fa0a8a3c337ed2d200166d6926ab23c14f8b2e","Linux >= 260f3ea141382386e97611e7c2029bc013088ab1 < e102ce0f4af99dff769a4b1b4daa4cc6bd5ad2d9","Linux >= 260f3ea141382386e97611e7c2029bc013088ab1 < 69632952aca04caa71e49953b6949fc04e788e67","Linux >= 260f3ea141382386e97611e7c2029bc013088ab1 < 7db2511fc601ca3a6e3fb1bdce02261c3c3167c3","Linux >= 260f3ea141382386e97611e7c2029bc013088ab1 < dd6f4ef6f8a37412909ad787c837332fb070159c","Linux 6.0"],"published":"2026-09-16","updated":"2026-09-16","sourceUpdated":"2026-09-16T11:17:05.797","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-89955","references":[{"url":"https://git.kernel.org/stable/c/31fa0a8a3c337ed2d200166d6926ab23c14f8b2e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/69632952aca04caa71e49953b6949fc04e788e67","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7db2511fc601ca3a6e3fb1bdce02261c3c3167c3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dd6f4ef6f8a37412909ad787c837332fb070159c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e102ce0f4af99dff769a4b1b4daa4cc6bd5ad2d9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-16T10:53:53.961Z","epss":0.002,"epssPercentile":0.10117,"slug":"CVE-2026-89955","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}