{"schema":"threatline.record/2","record":{"id":"CVE-2026-98841","aliases":[],"summary":"virt: vmgenid: set driver_data before registering notification handlers","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nvirt: vmgenid: set driver_data before registering notification handlers\n\nBoth probe paths register their notification handler before assigning\ndriver_data, which the handler dereferences.\n\nIn the devicetree path, the notification IRQ can fire as soon as\ndevm_request_irq() registers the handler: the interrupt may already be\npending at probe time, for example when a VMM injects the\ngeneration-changed notification while restoring a guest from a snapshot\nthat was taken before the driver had probed (Firecracker does exactly\nthis on snapshot restore). The IRQ is also requested with IRQF_SHARED,\nso another device sharing the line can trigger the handler just as\nearly. The handler then calls vmgenid_notify(), which dereferences the\nstill-NULL driver_data and panics:\n\n  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010\n  CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.18.38+ #1 PREEMPT(none)\n  Hardware name: linux,dummy-virt (DT)\n  pc : vmgenid_notify.isra.0+0x24/0x8c\n  lr : vmgenid_of_irq_handler+0x14/0x34\n  Call trace:\n   vmgenid_notify.isra.0+0x24/0x8c (P)\n   vmgenid_of_irq_handler+0x14/0x34\n   __handle_irq_event_percpu+0x44/0x1bc\n   handle_irq_event+0x4c/0xb4\n   handle_fasteoi_irq+0xf8/0x1f8\n\nThe ACPI path has the same ordering problem: the handler is installed\nwith acpi_install_notify_handler() before driver_data is assigned.\nACPI notifications are dispatched asynchronously from a workqueue, so\nthe window is narrow, but a notification arriving between the two calls\nhits the same NULL dereference.\n\nAssign driver_data before registering the handlers. The state is fully\ninitialized at that point, so the handlers are safe to run. Should\nregistration fail, the probe error path leaves no dangling pointer\nbehind: the driver core clears driver_data in device_unbind_cleanup().","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98841","source_modified_at":"2026-10-19T09:26:33.492Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"e07606713a908eee8099883c8c830ebe33aaf748","lessThan":"538fe5efaa9704ad820ba34b4f9df135ca873d79","status":"affected","versionType":"git"},{"version":"e07606713a908eee8099883c8c830ebe33aaf748","lessThan":"7a1e8daeaa466c6aaffa223e1afe9cfeece0dd47","status":"affected","versionType":"git"},{"version":"e07606713a908eee8099883c8c830ebe33aaf748","lessThan":"8f42954ad8bf9bdbf574f2c437ad30cb2601f401","status":"affected","versionType":"git"},{"version":"e07606713a908eee8099883c8c830ebe33aaf748","lessThan":"9f8139c6145cf17d690d6c414d43b4c0bef632fb","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98841","source_modified_at":"2026-10-19T09:26:33.492Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"6.10","status":"affected"},{"version":"0","lessThan":"6.10","status":"unaffected","versionType":"semver"},{"version":"6.12.113","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.56","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.10","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98841","source_modified_at":"2026-10-19T09:26:33.492Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"538fe5efaa9704ad820ba34b4f9df135ca873d79","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98841","source_modified_at":"2026-10-19T09:26:33.492Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"7a1e8daeaa466c6aaffa223e1afe9cfeece0dd47","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98841","source_modified_at":"2026-10-19T09:26:33.492Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"8f42954ad8bf9bdbf574f2c437ad30cb2601f401","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98841","source_modified_at":"2026-10-19T09:26:33.492Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"9f8139c6145cf17d690d6c414d43b4c0bef632fb","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00168,"percentile":0.0575,"score_date":"2026-10-23"},"published_at":"2026-10-18T15:50:15.224Z","modified_at":"2026-10-19T09:26:33.492Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98841","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:26:33.492Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98841","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/538fe5efaa9704ad820ba34b4f9df135ca873d79"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/7a1e8daeaa466c6aaffa223e1afe9cfeece0dd47"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/8f42954ad8bf9bdbf574f2c437ad30cb2601f401"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/9f8139c6145cf17d690d6c414d43b4c0bef632fb"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:26:33.492Z","content_hash":"97c95fc5466d4365ade29fbb559f06b2da89d0afc2d8aec3933430c54c1292a8"}}