{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-50036", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-10-21T12:17:06.070Z", "datePublished": "2024-10-21T19:39:37.135Z", "dateUpdated": "2026-08-05T11:41:09.713Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:41:09.713Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: do not delay dst_entries_add() in dst_release()\n\ndst_entries_add() uses per-cpu data that might be freed at netns\ndismantle from ip6_route_net_exit() calling dst_entries_destroy()\n\nBefore ip6_route_net_exit() can be called, we release all\nthe dsts associated with this netns, via calls to dst_release(),\nwhich waits an rcu grace period before calling dst_destroy()\n\ndst_entries_add() use in dst_destroy() is racy, because\ndst_entries_destroy() could have been called already.\n\nDecrementing the number of dsts must happen sooner.\n\nNotes:\n\n1) in CONFIG_XFRM case, dst_destroy() can call\n dst_release_immediate(child), this might also cause UAF\n if the child does not have DST_NOCOUNT set.\n IPSEC maintainers might take a look and see how to address this.\n\n2) There is also discussion about removing this count of dst,\n which might happen in future kernels." } ], "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 trigger is network-namespace dismantle — a local operation (`unshare -Urn` then exit, or `ip netns del`) that drives `cleanup_net()` → `ip6_route_net_exit()`; a remote peer can populate the counted IPv6 dsts but cannot cause the teardown itself.\nAC:L - The attacker controls both sides — it creates the counted dsts and triggers the teardown — and the \"race\" is structurally biased in the attacker's favor since `fib6_net_exit()`'s `dst_release()` calls precede `ip6_route_net_exit()` by microseconds while the deferred `dst_destroy()` waits a full RCU grace period; automated CI hit it accidentally, and the loop can be repeated indefinitely.\nPR:L - An unprivileged local user obtains CAP_NET_ADMIN in a private netns via user namespaces (`unshare -Urn`, enabled by default on Debian/Ubuntu/Fedora and inherent to container runtimes), which is sufficient to create the IPv6 dsts and destroy the namespace; no real root is needed.\nUI:N - The attacker performs every step itself — namespace creation, IPv6 traffic/exception-route generation, and namespace teardown — with no victim action required.\nS:U - The freed per-cpu memory and the resulting corruption are kernel objects within the same security authority; no hypervisor, IOMMU, or sandbox boundary is crossed.\nC:H - This is a use-after-free: `percpu_counter_add_batch()` reads `this_cpu_read(*fbc->counters)` from `free_percpu()`'d memory that another subsystem has since reallocated, and the slow path folds that stolen value into `fbc->count`, which is observable via `dst_entries_get_slow()`; escalating the per-cpu `percpu_ref` decrement to a real object UAF yields arbitrary kernel read.\nI:H - The same code path performs a `this_cpu_try_cmpxchg` **write** into the freed/reallocated per-cpu slot — a groomable, repeatable decrement primitive on arbitrary per-cpu state — and once `fbc->counters` is NULLed it writes at per-cpu offset 0, corrupting `pcpu_hot.current_task` on x86_64, which is directly leveragable for control-flow hijack and privilege escalation.\nA:H - The reported failure is a KASAN use-after-free splat during netns dismantle, and corrupting freed per-cpu memory or the `current_task` pointer reliably produces an oops/panic; the teardown loop can be repeated at will." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/core/dst.c" ], "versions": [ { "version": "f88649721268999bdff09777847080a52004f691", "lessThan": "547087307bc19417b4f2bc85ba9664a3e8db5a6a", "status": "affected", "versionType": "git" }, { "version": "f88649721268999bdff09777847080a52004f691", "lessThan": "e3915f028b1f1c37e87542e5aadd33728c259d96", "status": "affected", "versionType": "git" }, { "version": "f88649721268999bdff09777847080a52004f691", "lessThan": "a60db84f772fc3a906c6c4072f9207579c41166f", "status": "affected", "versionType": "git" }, { "version": "f88649721268999bdff09777847080a52004f691", "lessThan": "eae7435b48ffc8e9be0ff9cfeae40af479a609dd", "status": "affected", "versionType": "git" }, { "version": "f88649721268999bdff09777847080a52004f691", "lessThan": "3c7c918ec0aa3555372c5a57f18780b7a96c5cfc", "status": "affected", "versionType": "git" }, { "version": "f88649721268999bdff09777847080a52004f691", "lessThan": "ac888d58869bb99753e7652be19a151df9ecb35d", "status": "affected", "versionType": "git" }, { "version": "86e48c03d774e01ccd71ecba4fc4b5c2bc0b5b41", "status": "affected", "versionType": "git" }, { "version": "591b1e1bb40152e22cee757f493046a0ca946bf8", "status": "affected", "versionType": "git" }, { "version": "df90819dafcd6b97fc665f63a15752a570e227a2", "status": "affected", "versionType": "git" }, { "version": "9a4fe697023dbe6c25caa1f8b2153af869a29bd2", "status": "affected", "versionType": "git" }, { "version": "3.10.50", "lessThan": "3.11", "status": "affected", "versionType": "semver" }, { "version": "3.12.26", "lessThan": "3.13", "status": "affected", "versionType": "semver" }, { "version": "3.14.14", "lessThan": "3.15", "status": "affected", "versionType": "semver" }, { "version": "3.15.7", "lessThan": "3.16", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/core/dst.c" ], "versions": [ { "version": "3.16", "status": "affected" }, { "version": "0", "lessThan": "3.16", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.230", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.172", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.117", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.57", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.11.4", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12", "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": "3.16", "versionEndExcluding": "5.10.230" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "5.15.172" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "6.1.117" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "6.6.57" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "6.11.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "6.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.12.26" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.14.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.15.7" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/547087307bc19417b4f2bc85ba9664a3e8db5a6a" }, { "url": "https://git.kernel.org/stable/c/e3915f028b1f1c37e87542e5aadd33728c259d96" }, { "url": "https://git.kernel.org/stable/c/a60db84f772fc3a906c6c4072f9207579c41166f" }, { "url": "https://git.kernel.org/stable/c/eae7435b48ffc8e9be0ff9cfeae40af479a609dd" }, { "url": "https://git.kernel.org/stable/c/3c7c918ec0aa3555372c5a57f18780b7a96c5cfc" }, { "url": "https://git.kernel.org/stable/c/ac888d58869bb99753e7652be19a151df9ecb35d" } ], "title": "net: do not delay dst_entries_add() in dst_release()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-50036", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-10-22T13:25:25.259782Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-10-22T13:28:44.921Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T22:24:42.427Z" } } ] } }