{"api_version":"1","generated_at":"2026-10-27T10:17:19+00:00","cve":"CVE-2026-99054","urls":{"html":"https://cve.report/CVE-2026-99054","api":"https://cve.report/api/cve/CVE-2026-99054.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-99054","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-99054"},"summary":{"title":"tipc: destroy topsrv workqueues before closing connections","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: destroy topsrv workqueues before closing connections\n\ntipc_topsrv_stop() closed subscriber connections while the topology\nserver's send and receive workqueues were still running. Socket\ncallbacks and subscription events could then queue more work, and\nin-flight send/recv work could drop the last connection reference\nduring the conn_idr walk.\n\nThat race produced several teardown failures: refcount_t addition on\n0 from conn_get() on a connection whose release was blocked on\nidr_lock, a subsequent use-after-free in tipc_conn_close(),\nqueue_work() on an already destroyed workqueue from the listener\ndata-ready callback, and an RCU stall in tipc_topsrv_exit_net()\nwhile the walk spun under idr_lock.\n\nClear srv->listener under idr_lock so it acts as a shutdown flag,\nskip queue_work() once it is NULL, destroy the workqueues to flush\nin-flight work, and only then close the remaining connections.\nRefuse tipc_conn_lookup() after that flag is cleared, and drop\nidr_lock when the teardown walk finds no connection, so an\nin-flight subscription event cannot pin idr_in_use while the\nwalk holds the lock.\n\nv3 supersedes the narrower in-thread diff Tung Quang Nguyen\nposted on 2026-09-23. It keeps his teardown order and adds the\nlookup refusal and the empty-idr unlock.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-10-23 13:17:29","updated_at":"2026-10-24 14:16:54"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"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","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/da9c16568bc79140a54c1f5fcf07a0305df47b37","name":"https://git.kernel.org/stable/c/da9c16568bc79140a54c1f5fcf07a0305df47b37","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/0af8780bdfdfc91fb9127bddb9c48fab67dc9d9e","name":"https://git.kernel.org/stable/c/0af8780bdfdfc91fb9127bddb9c48fab67dc9d9e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7f796bb3b440d7f1b14c0e3b520462eb34f553af","name":"https://git.kernel.org/stable/c/7f796bb3b440d7f1b14c0e3b520462eb34f553af","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3acdd44385bc7e2e57605e073691ce69cc5a960d","name":"https://git.kernel.org/stable/c/3acdd44385bc7e2e57605e073691ce69cc5a960d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/fb717c536af2aafeca520ff11d1e0f25f7ab8fa9","name":"https://git.kernel.org/stable/c/fb717c536af2aafeca520ff11d1e0f25f7ab8fa9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-99054","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99054","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f 7f796bb3b440d7f1b14c0e3b520462eb34f553af git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f da9c16568bc79140a54c1f5fcf07a0305df47b37 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f 0af8780bdfdfc91fb9127bddb9c48fab67dc9d9e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f fb717c536af2aafeca520ff11d1e0f25f7ab8fa9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f 3acdd44385bc7e2e57605e073691ce69cc5a960d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3.11","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 3.11 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.160 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.113 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.57 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.11 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/tipc/topsrv.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"7f796bb3b440d7f1b14c0e3b520462eb34f553af","status":"affected","version":"c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f","versionType":"git"},{"lessThan":"da9c16568bc79140a54c1f5fcf07a0305df47b37","status":"affected","version":"c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f","versionType":"git"},{"lessThan":"0af8780bdfdfc91fb9127bddb9c48fab67dc9d9e","status":"affected","version":"c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f","versionType":"git"},{"lessThan":"fb717c536af2aafeca520ff11d1e0f25f7ab8fa9","status":"affected","version":"c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f","versionType":"git"},{"lessThan":"3acdd44385bc7e2e57605e073691ce69cc5a960d","status":"affected","version":"c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/tipc/topsrv.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"3.11"},{"lessThan":"3.11","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.160","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.113","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.57","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.11","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.160","versionStartIncluding":"3.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.113","versionStartIncluding":"3.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.57","versionStartIncluding":"3.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.11","versionStartIncluding":"3.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3","versionStartIncluding":"3.11","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: destroy topsrv workqueues before closing connections\n\ntipc_topsrv_stop() closed subscriber connections while the topology\nserver's send and receive workqueues were still running. Socket\ncallbacks and subscription events could then queue more work, and\nin-flight send/recv work could drop the last connection reference\nduring the conn_idr walk.\n\nThat race produced several teardown failures: refcount_t addition on\n0 from conn_get() on a connection whose release was blocked on\nidr_lock, a subsequent use-after-free in tipc_conn_close(),\nqueue_work() on an already destroyed workqueue from the listener\ndata-ready callback, and an RCU stall in tipc_topsrv_exit_net()\nwhile the walk spun under idr_lock.\n\nClear srv->listener under idr_lock so it acts as a shutdown flag,\nskip queue_work() once it is NULL, destroy the workqueues to flush\nin-flight work, and only then close the remaining connections.\nRefuse tipc_conn_lookup() after that flag is cleared, and drop\nidr_lock when the teardown walk finds no connection, so an\nin-flight subscription event cannot pin idr_in_use while the\nwalk holds the lock.\n\nv3 supersedes the narrower in-thread diff Tung Quang Nguyen\nposted on 2026-09-23. It keeps his teardown order and adds the\nlookup refusal and the empty-idr unlock."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - `unshare(CLONE_NEWUSER|CLONE_NEWNET)` creates the per-net TIPC server; local `socket(AF_TIPC)`, `connect(TIPC_TOP_SRV)`, and `send()` churn followed by exit drives `cleanup_net()` -> `tipc_topsrv_exit_net()` -> patched `tipc_topsrv_stop()`. No remote message can cause the required namespace teardown.\nAC:L - The attacker controls both sides of the race: worker threads repeatedly create and close topology subscriptions while their process exits the network namespace, racing `rwork`/`swork` and socket callbacks against `tipc_topsrv_stop()`. No victim or hardware state is required.\nPR:L - `tipc_sk_create()`, `tipc_connect()`, and `tipc_conn_rcv_sub()` have no capability or authentication gate; an ordinary user can obtain the `CAP_SYS_ADMIN` needed for `CLONE_NEWNET` inside a new user namespace. No init-namespace privilege is required.\nUI:N - The attacker creates the namespaces, opens and floods `TIPC_TOP_SRV` connections, closes them, and exits to start `cleanup_net()` without any victim action.\nS:U - The freed `tipc_conn` and workqueue objects belong to the host kernel, and exploitation of `tipc_topsrv_stop()` affects that same kernel authority without crossing a VM, IOMMU, or other security boundary.\nC:H - `tipc_conn_kref_release()` frees `con` while teardown retains its address; `tipc_conn_close()` then reads `con->sock->sk` and follows reclaimed subscription and socket pointers. Reclaiming this object permits attacker-controlled pointer dereferences usable as kernel-memory read primitives.\nI:H - After the free, `tipc_conn_close()` modifies reclaimed `con->flags`, writes through `sk->sk_user_data`, processes reclaimed subscription lists, and calls `kernel_sock_shutdown()` through `con->sock->ops`. These provide memory-write and control-flow primitives.\nA:H - The reported race produced a page fault in `tipc_conn_close()`, `queue_work()` on a destroyed receive workqueue, and an RCU stall in `tipc_topsrv_exit_net()`; these paths can oops, panic, or wedge the system."}]}],"providerMetadata":{"dateUpdated":"2026-10-24T14:10:14.659Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/7f796bb3b440d7f1b14c0e3b520462eb34f553af"},{"url":"https://git.kernel.org/stable/c/da9c16568bc79140a54c1f5fcf07a0305df47b37"},{"url":"https://git.kernel.org/stable/c/0af8780bdfdfc91fb9127bddb9c48fab67dc9d9e"},{"url":"https://git.kernel.org/stable/c/fb717c536af2aafeca520ff11d1e0f25f7ab8fa9"},{"url":"https://git.kernel.org/stable/c/3acdd44385bc7e2e57605e073691ce69cc5a960d"}],"title":"tipc: destroy topsrv workqueues before closing connections","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-99054","datePublished":"2026-10-23T12:22:36.886Z","dateReserved":"2026-09-25T10:25:14.388Z","dateUpdated":"2026-10-24T14:10:14.659Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-23 13:17:29","lastModifiedDate":"2026-10-24 14:16:54","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"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","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"99054","Ordinal":"1","Title":"tipc: destroy topsrv workqueues before closing connections","CVE":"CVE-2026-99054","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"99054","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: destroy topsrv workqueues before closing connections\n\ntipc_topsrv_stop() closed subscriber connections while the topology\nserver's send and receive workqueues were still running. Socket\ncallbacks and subscription events could then queue more work, and\nin-flight send/recv work could drop the last connection reference\nduring the conn_idr walk.\n\nThat race produced several teardown failures: refcount_t addition on\n0 from conn_get() on a connection whose release was blocked on\nidr_lock, a subsequent use-after-free in tipc_conn_close(),\nqueue_work() on an already destroyed workqueue from the listener\ndata-ready callback, and an RCU stall in tipc_topsrv_exit_net()\nwhile the walk spun under idr_lock.\n\nClear srv->listener under idr_lock so it acts as a shutdown flag,\nskip queue_work() once it is NULL, destroy the workqueues to flush\nin-flight work, and only then close the remaining connections.\nRefuse tipc_conn_lookup() after that flag is cleared, and drop\nidr_lock when the teardown walk finds no connection, so an\nin-flight subscription event cannot pin idr_in_use while the\nwalk holds the lock.\n\nv3 supersedes the narrower in-thread diff Tung Quang Nguyen\nposted on 2026-09-23. It keeps his teardown order and adds the\nlookup refusal and the empty-idr unlock.","Type":"Description","Title":"tipc: destroy topsrv workqueues before closing connections"}]}}}