{"schema":"threatline.record/2","record":{"id":"CVE-2026-97996","aliases":[],"summary":"virtio: fix use-after-free in unregister_virtio_device()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nvirtio: fix use-after-free in unregister_virtio_device()\n\ndevice_unregister() is device_del() plus put_device(). When the caller\nholds no extra reference, that drops the last one and runs the release\ncallback, which for several transports frees the memory the embedded\nstruct virtio_device sits in. unregister_virtio_device() then calls\nvirtio_debug_device_exit(), which reads dev->debugfs_dir out of the freed\nobject.\n\nAffected transports are the ones whose release callback frees and whose\nremove path takes no reference: virtio_mmio, virtio_vdpa, virtio_uml,\nmlxbf-tmfifo and virtio_ccw. virtio_pci is unaffected because\nvirtio_pci_remove() brackets the call with get_device() and put_device().\n\nRemove the debugfs entries before the device can go away. They are only\naccessed through the protected debugfs interface, so\ndebugfs_remove_recursive() waits for in-progress file operations before\nreturning. Tearing them down while the device is still alive is therefore\nsafe.\n\nReproduced on User-Mode Linux with CONFIG_KASAN and CONFIG_VIRTIO_DEBUG\nby unbinding a virtio-uml device:\n\n  BUG: KASAN: slab-use-after-free in virtio_debug_device_exit+0x36/0x4d\n  Read of size 8 at addr 00000000616e0b10 by task init/1\n   __asan_report_load8_noabort\n   virtio_debug_device_exit+0x36/0x4d\n   unregister_virtio_device+0x48/0x75\n   virtio_uml_remove\n   platform_remove\n   device_release_driver_internal\n   unbind_store\n\n  Freed by task 1:\n   kfree\n   virtio_uml_release_dev\n   device_release\n   kobject_put\n   put_device\n   device_unregister\n\nWith this applied, the report is gone and unbind is clean.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97996","source_modified_at":"2026-10-19T09:12:03.153Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"96a8326d69fffd7e8c2eb737dc060d8009a33b39","lessThan":"951cad50cba89e736afdee4a730e0e52f9245c9b","status":"affected","versionType":"git"},{"version":"96a8326d69fffd7e8c2eb737dc060d8009a33b39","lessThan":"77dbd10a701a30fdfea5c3bb7a29163128f9a9c7","status":"affected","versionType":"git"},{"version":"96a8326d69fffd7e8c2eb737dc060d8009a33b39","lessThan":"caf042153016d651b55d0fb4a63cdf7d0d23dee2","status":"affected","versionType":"git"},{"version":"96a8326d69fffd7e8c2eb737dc060d8009a33b39","lessThan":"3f9a0fceb730f5107d52421ead5568eae25a0049","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97996","source_modified_at":"2026-10-19T09:12:03.153Z","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":"6.12.111","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.53","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.7","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-2026-97996","source_modified_at":"2026-10-19T09:12:03.153Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"951cad50cba89e736afdee4a730e0e52f9245c9b","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97996","source_modified_at":"2026-10-19T09:12:03.153Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"77dbd10a701a30fdfea5c3bb7a29163128f9a9c7","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97996","source_modified_at":"2026-10-19T09:12:03.153Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"3f9a0fceb730f5107d52421ead5568eae25a0049","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00168,"percentile":0.05755,"score_date":"2026-10-23"},"published_at":"2026-09-25T10:23:26.913Z","modified_at":"2026-10-19T09:12:03.153Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-97996","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:12:03.153Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-97996","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/951cad50cba89e736afdee4a730e0e52f9245c9b"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/77dbd10a701a30fdfea5c3bb7a29163128f9a9c7"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/caf042153016d651b55d0fb4a63cdf7d0d23dee2"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/3f9a0fceb730f5107d52421ead5568eae25a0049"}],"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":"2026-10-19T09:12:03.153Z","content_hash":"46fa61ef4aab7d21de4b0499d5cc0c6a9b2c137f644ea2255e6ad9fedb023fc7"}}