{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-98112", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.316Z", "datePublished": "2026-09-25T10:35:59.319Z", "dateUpdated": "2026-09-25T14:42:06.515Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-25T14:42:06.515Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix listener task lifetime on netdev events\n\nThe listener thread exits when its listening socket is shutdown. The\nnetdevice notifier shuts down the socket before calling kthread_stop(), so\nthe task_struct can be freed before kthread_stop() gets its reference.\n\nCreate the listener in a stopped state and hold an extra task_struct\nreference until kthread_stop_put() completes. Also stop and release\nlisteners before freeing their interface records during TCP teardown."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The bug is kthread_stop() on an already-exited listener, reached from ksmbd_netdev_event(NETDEV_DOWN). That event comes from local rtnetlink link up/down. No SMB message carries attacker data to this path, so it is not remote.\nAC:L - The attacker starts the race: kernel_sock_shutdown() makes the listener exit before kthread_stop() takes its reference. The attacker can repeat it at will by toggling a same-named link. Each NETDEV_UP makes create_socket() start a new listener, so the narrow window can be retried as many times as needed.\nPR:L - ksmbd_netdev_event() matches iface names without checking the network namespace. An unprivileged user in `unshare -Urn` can down their own `lo`, or a veth named like a host interface, with only CAP_NET_ADMIN inside the user namespace, and so run the teardown of the host listener.\nUI:N - Nothing is needed from an admin or victim beyond ksmbd already running. The attacker sends the netlink link up/down requests themselves inside their own network namespace.\nS:U - This is memory corruption inside the kernel that leads to local privilege escalation or a crash within the same kernel authority. It does not cross a hypervisor or other separate security boundary.\nC:H - After the listener task_struct is freed and reallocated, kthread_stop() reads to_kthread(k) and kthread->result through a dangling pointer. The attacker can control the reclaimed object, which enables kernel memory disclosure.\nI:H - kthread_stop() writes to freed memory: it increments the refcount, does set_bit() on kthread->flags, then calls wake_up_process() and put_task_struct() on the stale task. This corrupts whatever object has reclaimed the memory and can be groomed into a write or an extra free.\nA:H - Using the freed task_struct/kthread in kthread_stop() under rtnl can cause an oops, a refcount underflow or a hang. Each trigger also tears down ksmbd's real host listener on port 445, so the server stops accepting connections."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/server/transport_tcp.c"], "versions": [{"version": "3316a8fc840d82fad5efcf76ad0ea3f76fdca209", "lessThan": "40581f10c1e56238b157af5f260b8f9518a0cbc1", "status": "affected", "versionType": "git"}, {"version": "3316a8fc840d82fad5efcf76ad0ea3f76fdca209", "lessThan": "a506290f59e1c6ce9ac0a13158640bb8fee93471", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/server/transport_tcp.c"], "versions": [{"version": "6.19", "status": "affected"}, {"version": "0", "lessThan": "6.19", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.7", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3-rc2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.2.7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.3-rc2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/40581f10c1e56238b157af5f260b8f9518a0cbc1"}, {"url": "https://git.kernel.org/stable/c/a506290f59e1c6ce9ac0a13158640bb8fee93471"}], "title": "ksmbd: fix listener task lifetime on netdev events", "x_generator": {"engine": "bippy-1.2.0"}}}}