CVE-2021-47163 (GCVE-0-2021-47163)
Vulnerability from cvelistv5
Published
2024-03-25 09:16
Modified
2026-08-05 08:46
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: tipc: wait and exit until all work queues are done On some host, a crash could be triggered simply by repeating these commands several times: # modprobe tipc # tipc bearer enable media udp name UDP1 localip 127.0.0.1 # rmmod tipc [] BUG: unable to handle kernel paging request at ffffffffc096bb00 [] Workqueue: events 0xffffffffc096bb00 [] Call Trace: [] ? process_one_work+0x1a7/0x360 [] ? worker_thread+0x30/0x390 [] ? create_worker+0x1a0/0x1a0 [] ? kthread+0x116/0x130 [] ? kthread_flush_work_fn+0x10/0x10 [] ? ret_from_fork+0x35/0x40 When removing the TIPC module, the UDP tunnel sock will be delayed to release in a work queue as sock_release() can't be done in rtnl_lock(). If the work queue is schedule to run after the TIPC module is removed, kernel will crash as the work queue function cleanup_beareri() code no longer exists when trying to invoke it. To fix it, this patch introduce a member wq_count in tipc_net to track the numbers of work queues in schedule, and wait and exit until all work queues are done in tipc_exit_net().
References
Impacted products
Vendor Product Version
Linux Linux Version: d0f91938bede204a343473792529e0db7d599836
Version: d0f91938bede204a343473792529e0db7d599836
Version: d0f91938bede204a343473792529e0db7d599836
Version: d0f91938bede204a343473792529e0db7d599836
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-47163",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-04-01T19:41:39.688056Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-06-04T17:15:00.578Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T05:24:39.948Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/5195ec5e365a2a9331bfeb585b613a6e94f98dba"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/04c26faa51d1e2fe71cf13c45791f5174c37f986"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/tipc/core.c",
            "net/tipc/core.h",
            "net/tipc/udp_media.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa",
              "status": "affected",
              "version": "d0f91938bede204a343473792529e0db7d599836",
              "versionType": "git"
            },
            {
              "lessThan": "5195ec5e365a2a9331bfeb585b613a6e94f98dba",
              "status": "affected",
              "version": "d0f91938bede204a343473792529e0db7d599836",
              "versionType": "git"
            },
            {
              "lessThan": "b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d",
              "status": "affected",
              "version": "d0f91938bede204a343473792529e0db7d599836",
              "versionType": "git"
            },
            {
              "lessThan": "04c26faa51d1e2fe71cf13c45791f5174c37f986",
              "status": "affected",
              "version": "d0f91938bede204a343473792529e0db7d599836",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/tipc/core.c",
            "net/tipc/core.h",
            "net/tipc/udp_media.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.1"
            },
            {
              "lessThan": "4.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.4.*",
              "status": "unaffected",
              "version": "5.4.124",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.12.*",
              "status": "unaffected",
              "version": "5.12.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.13",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.4.124",
                  "versionStartIncluding": "4.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.42",
                  "versionStartIncluding": "4.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.12.9",
                  "versionStartIncluding": "4.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.13",
                  "versionStartIncluding": "4.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: wait and exit until all work queues are done\n\nOn some host, a crash could be triggered simply by repeating these\ncommands several times:\n\n  # modprobe tipc\n  # tipc bearer enable media udp name UDP1 localip 127.0.0.1\n  # rmmod tipc\n\n  [] BUG: unable to handle kernel paging request at ffffffffc096bb00\n  [] Workqueue: events 0xffffffffc096bb00\n  [] Call Trace:\n  []  ? process_one_work+0x1a7/0x360\n  []  ? worker_thread+0x30/0x390\n  []  ? create_worker+0x1a0/0x1a0\n  []  ? kthread+0x116/0x130\n  []  ? kthread_flush_work_fn+0x10/0x10\n  []  ? ret_from_fork+0x35/0x40\n\nWhen removing the TIPC module, the UDP tunnel sock will be delayed to\nrelease in a work queue as sock_release() can\u0027t be done in rtnl_lock().\nIf the work queue is schedule to run after the TIPC module is removed,\nkernel will crash as the work queue function cleanup_beareri() code no\nlonger exists when trying to invoke it.\n\nTo fix it, this patch introduce a member wq_count in tipc_net to track\nthe numbers of work queues in schedule, and  wait and exit until all\nwork queues are done in tipc_exit_net()."
        }
      ],
      "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 - The bug is reached via local tipc generic-netlink bearer enable/disable and netns teardown (or local rmmod of tipc); it is not triggered by processing unsolicited remote TIPC/UDP packets.\nAC:L - The attacker controls both sides of the race by enabling a UDP bearer and then destroying the netns (or repeating modprobe/enable/rmmod), so the pending cleanup_bearer work is reliably left running after tipc_exit_net returns.\nPR:L - At the time of this bug, TIPCv2 bearer mutators lacked GENL_ADMIN_PERM, and an unprivileged user can create a user+net namespace (unshare -Urn) and enable a tipc UDP bearer whenever tipc is loaded; CAP_NET_ADMIN in a userns is also Low per guidance.\nUI:N - No victim action is required; the attacker enables the bearer and tears down their own netns (or unloads tipc) entirely on their own.\nS:U - Impact is a host-kernel use-after-free/crash within the same kernel security authority; there is no VM, IOMMU, or sandbox boundary crossing.\nC:H - tipc_exit_net returns without waiting for cleanup_bearer while kernel UDP sockets hold no netns refcount, so the work runs against freed net/module state; this UAF can be leveraged for arbitrary kernel memory disclosure.\nI:H - The same UAF (and the module-unload path that invokes freed cleanup_bearer text via the workqueue) is memory corruption exploitable for write primitives and control-flow hijacking, not merely a clean crash.\nA:H - The reported failure is a kernel paging-request oops when the workqueue runs after tipc teardown/unload, and the netns UAF path likewise causes kernel crashes."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T08:46:27.215Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa"
        },
        {
          "url": "https://git.kernel.org/stable/c/5195ec5e365a2a9331bfeb585b613a6e94f98dba"
        },
        {
          "url": "https://git.kernel.org/stable/c/b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d"
        },
        {
          "url": "https://git.kernel.org/stable/c/04c26faa51d1e2fe71cf13c45791f5174c37f986"
        }
      ],
      "title": "tipc: wait and exit until all work queues are done",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2021-47163",
    "datePublished": "2024-03-25T09:16:16.676Z",
    "dateReserved": "2024-03-25T09:12:14.109Z",
    "dateUpdated": "2026-08-05T08:46:27.215Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"https://git.kernel.org/stable/c/d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://git.kernel.org/stable/c/5195ec5e365a2a9331bfeb585b613a6e94f98dba\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://git.kernel.org/stable/c/b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://git.kernel.org/stable/c/04c26faa51d1e2fe71cf13c45791f5174c37f986\", \"tags\": [\"x_transferred\"]}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2024-08-04T05:24:39.948Z\"}}, {\"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2021-47163\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2024-04-01T19:41:39.688056Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2024-05-23T19:01:20.842Z\"}, \"title\": \"CISA ADP Vulnrichment\"}], \"cna\": {\"title\": \"tipc: wait and exit until all work queues are done\", \"metrics\": [{\"cvssV3_1\": {\"version\": \"3.1\", \"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\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"AV:L - The bug is reached via local tipc generic-netlink bearer enable/disable and netns teardown (or local rmmod of tipc); it is not triggered by processing unsolicited remote TIPC/UDP packets.\\nAC:L - The attacker controls both sides of the race by enabling a UDP bearer and then destroying the netns (or repeating modprobe/enable/rmmod), so the pending cleanup_bearer work is reliably left running after tipc_exit_net returns.\\nPR:L - At the time of this bug, TIPCv2 bearer mutators lacked GENL_ADMIN_PERM, and an unprivileged user can create a user+net namespace (unshare -Urn) and enable a tipc UDP bearer whenever tipc is loaded; CAP_NET_ADMIN in a userns is also Low per guidance.\\nUI:N - No victim action is required; the attacker enables the bearer and tears down their own netns (or unloads tipc) entirely on their own.\\nS:U - Impact is a host-kernel use-after-free/crash within the same kernel security authority; there is no VM, IOMMU, or sandbox boundary crossing.\\nC:H - tipc_exit_net returns without waiting for cleanup_bearer while kernel UDP sockets hold no netns refcount, so the work runs against freed net/module state; this UAF can be leveraged for arbitrary kernel memory disclosure.\\nI:H - The same UAF (and the module-unload path that invokes freed cleanup_bearer text via the workqueue) is memory corruption exploitable for write primitives and control-flow hijacking, not merely a clean crash.\\nA:H - The reported failure is a kernel paging-request oops when the workqueue runs after tipc teardown/unload, and the netns UAF path likewise causes kernel crashes.\"}]}], \"affected\": [{\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"d0f91938bede204a343473792529e0db7d599836\", \"lessThan\": \"d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"d0f91938bede204a343473792529e0db7d599836\", \"lessThan\": \"5195ec5e365a2a9331bfeb585b613a6e94f98dba\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"d0f91938bede204a343473792529e0db7d599836\", \"lessThan\": \"b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"d0f91938bede204a343473792529e0db7d599836\", \"lessThan\": \"04c26faa51d1e2fe71cf13c45791f5174c37f986\", \"versionType\": \"git\"}], \"programFiles\": [\"net/tipc/core.c\", \"net/tipc/core.h\", \"net/tipc/udp_media.c\"], \"defaultStatus\": \"unaffected\"}, {\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"4.1\"}, {\"status\": \"unaffected\", \"version\": \"0\", \"lessThan\": \"4.1\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"5.4.124\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.4.*\"}, {\"status\": \"unaffected\", \"version\": \"5.10.42\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.10.*\"}, {\"status\": \"unaffected\", \"version\": \"5.12.9\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.12.*\"}, {\"status\": \"unaffected\", \"version\": \"5.13\", \"versionType\": \"original_commit_for_fix\", \"lessThanOrEqual\": \"*\"}], \"programFiles\": [\"net/tipc/core.c\", \"net/tipc/core.h\", \"net/tipc/udp_media.c\"], \"defaultStatus\": \"affected\"}], \"references\": [{\"url\": \"https://git.kernel.org/stable/c/d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa\"}, {\"url\": \"https://git.kernel.org/stable/c/5195ec5e365a2a9331bfeb585b613a6e94f98dba\"}, {\"url\": \"https://git.kernel.org/stable/c/b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d\"}, {\"url\": \"https://git.kernel.org/stable/c/04c26faa51d1e2fe71cf13c45791f5174c37f986\"}], \"x_generator\": {\"engine\": \"bippy-1.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"In the Linux kernel, the following vulnerability has been resolved:\\n\\ntipc: wait and exit until all work queues are done\\n\\nOn some host, a crash could be triggered simply by repeating these\\ncommands several times:\\n\\n  # modprobe tipc\\n  # tipc bearer enable media udp name UDP1 localip 127.0.0.1\\n  # rmmod tipc\\n\\n  [] BUG: unable to handle kernel paging request at ffffffffc096bb00\\n  [] Workqueue: events 0xffffffffc096bb00\\n  [] Call Trace:\\n  []  ? process_one_work+0x1a7/0x360\\n  []  ? worker_thread+0x30/0x390\\n  []  ? create_worker+0x1a0/0x1a0\\n  []  ? kthread+0x116/0x130\\n  []  ? kthread_flush_work_fn+0x10/0x10\\n  []  ? ret_from_fork+0x35/0x40\\n\\nWhen removing the TIPC module, the UDP tunnel sock will be delayed to\\nrelease in a work queue as sock_release() can\u0027t be done in rtnl_lock().\\nIf the work queue is schedule to run after the TIPC module is removed,\\nkernel will crash as the work queue function cleanup_beareri() code no\\nlonger exists when trying to invoke it.\\n\\nTo fix it, this patch introduce a member wq_count in tipc_net to track\\nthe numbers of work queues in schedule, and  wait and exit until all\\nwork queues are done in tipc_exit_net().\"}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.4.124\", \"versionStartIncluding\": \"4.1\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.10.42\", \"versionStartIncluding\": \"4.1\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.12.9\", \"versionStartIncluding\": \"4.1\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.13\", \"versionStartIncluding\": \"4.1\"}], \"operator\": \"OR\"}]}], \"providerMetadata\": {\"orgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"shortName\": \"Linux\", \"dateUpdated\": \"2026-08-05T08:46:27.215Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2021-47163\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-08-05T08:46:27.215Z\", \"dateReserved\": \"2024-03-25T09:12:14.109Z\", \"assignerOrgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"datePublished\": \"2024-03-25T09:16:16.676Z\", \"assignerShortName\": \"Linux\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.