Vulnerability-Lookup

CVE-2026-64424 (GCVE-0-2026-64424)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:51 – Updated: 2026-07-25 08:51

Title

netpoll: fix a use-after-free on shutdown path

Summary

In the Linux kernel, the following vulnerability has been resolved: netpoll: fix a use-after-free on shutdown path There is a use-after-free error on netpoll, which is clearly detected by KASAN. BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3b/0x80 Read of size 1 at addr ... by task kworker/9:1 Workqueue: events queue_process Call Trace: skb_dequeue+0x1e/0xb0 queue_process+0x2c/0x600 process_scheduled_works+0x4b6/0x850 worker_thread+0x414/0x5a0 Allocated by task 242: __netpoll_setup+0x201/0x4a0 netpoll_setup+0x249/0x550 enabled_store+0x32f/0x380 Freed by task 0: kfree+0x1b7/0x540 rcu_core+0x3f8/0x7a0 The problem happens when there is a pending TX worker running in parallel with the cleanup path. This is what happens on netpoll shutdown path: 1) __netpoll_cleanup() is called 2) set dev->npinfo to NULL 3) call_rcu() with rcu_cleanup_netpoll_info() 3.1) rcu_cleanup_netpoll_info() tries to cancel all workers with cancel_delayed_work(), but doesn't wait for the worker to finish 4) and kfree(npinfo); Because 3.1) doesn't really cancel the work, as the comment says "we can't call cancel_delayed_work_sync here, as we are in softirq", the TX worker can run after 4). Tl;DR: queue_process() is not an RCU reader, it reaches npinfo through the work item via container_of(). Use disable_delayed_work_sync() to ensure the worker is completely stopped and prevent any future re-arming attempts. Once npinfo is set to NULL, senders will bail out and not queue new work. The disable flag ensures any in-flight re-arming attempts also fail silently. In the future, we can do the cleanup inline here without needing the npinfo->rcu rcu_head, but that is net-next material.

Severity

No CVSS data available.

Assigner

Linux

References

4 references

URL	Tags
https://git.kernel.org/stable/c/95ecc5b58042f6b67…
https://git.kernel.org/stable/c/a33f37f8d079da723…
https://git.kernel.org/stable/c/5ed09a108d93a3b00…
https://git.kernel.org/stable/c/45f1458a85017a023…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 38e6bc185d9544dfad1774b3f8902a0b061aea25 , < 95ecc5b58042f6b6743b589e6588f1cd7ba336aa (git) Affected: 38e6bc185d9544dfad1774b3f8902a0b061aea25 , < a33f37f8d079da7236ed7b7e2aed2a34ab81e7cf (git) Affected: 38e6bc185d9544dfad1774b3f8902a0b061aea25 , < 5ed09a108d93a3b002cc79823d9455b50c4a8be7 (git) Affected: 38e6bc185d9544dfad1774b3f8902a0b061aea25 , < 45f1458a85017a023f138b22ac5c76abd477db42 (git)
Linux	Linux	Affected: 3.6 Unaffected: 0 , < 3.6 (semver) Unaffected: 6.12.96 , ≤ 6.12.* (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2-rc2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/core/netpoll.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "95ecc5b58042f6b6743b589e6588f1cd7ba336aa",
              "status": "affected",
              "version": "38e6bc185d9544dfad1774b3f8902a0b061aea25",
              "versionType": "git"
            },
            {
              "lessThan": "a33f37f8d079da7236ed7b7e2aed2a34ab81e7cf",
              "status": "affected",
              "version": "38e6bc185d9544dfad1774b3f8902a0b061aea25",
              "versionType": "git"
            },
            {
              "lessThan": "5ed09a108d93a3b002cc79823d9455b50c4a8be7",
              "status": "affected",
              "version": "38e6bc185d9544dfad1774b3f8902a0b061aea25",
              "versionType": "git"
            },
            {
              "lessThan": "45f1458a85017a023f138b22ac5c76abd477db42",
              "status": "affected",
              "version": "38e6bc185d9544dfad1774b3f8902a0b061aea25",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/core/netpoll.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.6"
            },
            {
              "lessThan": "3.6",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.96",
                  "versionStartIncluding": "3.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.39",
                  "versionStartIncluding": "3.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.4",
                  "versionStartIncluding": "3.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2-rc2",
                  "versionStartIncluding": "3.6",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetpoll: fix a use-after-free on shutdown path\n\nThere is a use-after-free error on netpoll, which is clearly detected by\nKASAN.\n\n      BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3b/0x80\n      Read of size 1 at addr ... by task kworker/9:1\n      Workqueue: events queue_process\n      Call Trace:\n       skb_dequeue+0x1e/0xb0\n       queue_process+0x2c/0x600\n       process_scheduled_works+0x4b6/0x850\n       worker_thread+0x414/0x5a0\n      Allocated by task 242:\n       __netpoll_setup+0x201/0x4a0\n       netpoll_setup+0x249/0x550\n       enabled_store+0x32f/0x380\n      Freed by task 0:\n       kfree+0x1b7/0x540\n       rcu_core+0x3f8/0x7a0\n\nThe problem happens when there is a pending TX worker running in\nparallel with the cleanup path.\n\nThis is what happens on netpoll shutdown path:\n\n1) __netpoll_cleanup() is called\n2) set dev-\u003enpinfo to NULL\n3) call_rcu() with rcu_cleanup_netpoll_info()\n  3.1) rcu_cleanup_netpoll_info() tries to cancel all workers with\n       cancel_delayed_work(), but doesn\u0027t wait for the worker to finish\n4) and kfree(npinfo);\n\nBecause 3.1) doesn\u0027t really cancel the work, as the comment says \"we\ncan\u0027t call cancel_delayed_work_sync here, as we are in softirq\", the TX\nworker can run after 4).\n\nTl;DR: queue_process() is not an RCU reader, it reaches npinfo through\nthe work item via container_of().\n\nUse disable_delayed_work_sync() to ensure the worker is completely\nstopped and prevent any future re-arming attempts. Once npinfo is set\nto NULL, senders will bail out and not queue new work. The disable flag\nensures any in-flight re-arming attempts also fail silently.\n\nIn the future, we can do the cleanup inline here without needing the\nnpinfo-\u003ercu rcu_head, but that is net-next material."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-25T08:51:02.276Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/95ecc5b58042f6b6743b589e6588f1cd7ba336aa"
        },
        {
          "url": "https://git.kernel.org/stable/c/a33f37f8d079da7236ed7b7e2aed2a34ab81e7cf"
        },
        {
          "url": "https://git.kernel.org/stable/c/5ed09a108d93a3b002cc79823d9455b50c4a8be7"
        },
        {
          "url": "https://git.kernel.org/stable/c/45f1458a85017a023f138b22ac5c76abd477db42"
        }
      ],
      "title": "netpoll: fix a use-after-free on shutdown path",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64424",
    "datePublished": "2026-07-25T08:51:02.276Z",
    "dateReserved": "2026-07-19T15:36:31.787Z",
    "dateUpdated": "2026-07-25T08:51:02.276Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-64424",
      "date": "2026-07-26",
      "epss": "0.00168",
      "percentile": "0.06413"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-64424\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-07-25T10:17:26.483\",\"lastModified\":\"2026-07-25T10:17:26.483\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nnetpoll: fix a use-after-free on shutdown path\\n\\nThere is a use-after-free error on netpoll, which is clearly detected by\\nKASAN.\\n\\n      BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3b/0x80\\n      Read of size 1 at addr ... by task kworker/9:1\\n      Workqueue: events queue_process\\n      Call Trace:\\n       skb_dequeue+0x1e/0xb0\\n       queue_process+0x2c/0x600\\n       process_scheduled_works+0x4b6/0x850\\n       worker_thread+0x414/0x5a0\\n      Allocated by task 242:\\n       __netpoll_setup+0x201/0x4a0\\n       netpoll_setup+0x249/0x550\\n       enabled_store+0x32f/0x380\\n      Freed by task 0:\\n       kfree+0x1b7/0x540\\n       rcu_core+0x3f8/0x7a0\\n\\nThe problem happens when there is a pending TX worker running in\\nparallel with the cleanup path.\\n\\nThis is what happens on netpoll shutdown path:\\n\\n1) __netpoll_cleanup() is called\\n2) set dev-\u003enpinfo to NULL\\n3) call_rcu() with rcu_cleanup_netpoll_info()\\n  3.1) rcu_cleanup_netpoll_info() tries to cancel all workers with\\n       cancel_delayed_work(), but doesn\u0027t wait for the worker to finish\\n4) and kfree(npinfo);\\n\\nBecause 3.1) doesn\u0027t really cancel the work, as the comment says \\\"we\\ncan\u0027t call cancel_delayed_work_sync here, as we are in softirq\\\", the TX\\nworker can run after 4).\\n\\nTl;DR: queue_process() is not an RCU reader, it reaches npinfo through\\nthe work item via container_of().\\n\\nUse disable_delayed_work_sync() to ensure the worker is completely\\nstopped and prevent any future re-arming attempts. Once npinfo is set\\nto NULL, senders will bail out and not queue new work. The disable flag\\nensures any in-flight re-arming attempts also fail silently.\\n\\nIn the future, we can do the cleanup inline here without needing the\\nnpinfo-\u003ercu rcu_head, but that is net-next material.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"net/core/netpoll.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"38e6bc185d9544dfad1774b3f8902a0b061aea25\",\"lessThan\":\"95ecc5b58042f6b6743b589e6588f1cd7ba336aa\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"38e6bc185d9544dfad1774b3f8902a0b061aea25\",\"lessThan\":\"a33f37f8d079da7236ed7b7e2aed2a34ab81e7cf\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"38e6bc185d9544dfad1774b3f8902a0b061aea25\",\"lessThan\":\"5ed09a108d93a3b002cc79823d9455b50c4a8be7\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"38e6bc185d9544dfad1774b3f8902a0b061aea25\",\"lessThan\":\"45f1458a85017a023f138b22ac5c76abd477db42\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/core/netpoll.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"3.6\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"3.6\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.96\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.39\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.4\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2-rc2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/45f1458a85017a023f138b22ac5c76abd477db42\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/5ed09a108d93a3b002cc79823d9455b50c4a8be7\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/95ecc5b58042f6b6743b589e6588f1cd7ba336aa\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a33f37f8d079da7236ed7b7e2aed2a34ab81e7cf\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "suse_vex": {
      "aggregate_severity": "not set",
      "current_release_date": "2026-07-25T15:59:36Z",
      "cve": "CVE-2026-64424",
      "id": "CVE-2026-64424",
      "initial_release_date": "2026-07-25T15:59:36Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64424",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64424.json",
      "version": "2"
    }
  }
}

GHSA-4M75-5382-C595

Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-07-25 12:31

Details

In the Linux kernel, the following vulnerability has been resolved:

netpoll: fix a use-after-free on shutdown path

There is a use-after-free error on netpoll, which is clearly detected by KASAN.

  BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3b/0x80
  Read of size 1 at addr ... by task kworker/9:1
  Workqueue: events queue_process
  Call Trace:
   skb_dequeue+0x1e/0xb0
   queue_process+0x2c/0x600
   process_scheduled_works+0x4b6/0x850
   worker_thread+0x414/0x5a0
  Allocated by task 242:
   __netpoll_setup+0x201/0x4a0
   netpoll_setup+0x249/0x550
   enabled_store+0x32f/0x380
  Freed by task 0:
   kfree+0x1b7/0x540
   rcu_core+0x3f8/0x7a0

The problem happens when there is a pending TX worker running in parallel with the cleanup path.

This is what happens on netpoll shutdown path:

1) __netpoll_cleanup() is called 2) set dev->npinfo to NULL 3) call_rcu() with rcu_cleanup_netpoll_info() 3.1) rcu_cleanup_netpoll_info() tries to cancel all workers with cancel_delayed_work(), but doesn't wait for the worker to finish 4) and kfree(npinfo);

Because 3.1) doesn't really cancel the work, as the comment says "we can't call cancel_delayed_work_sync here, as we are in softirq", the TX worker can run after 4).

Tl;DR: queue_process() is not an RCU reader, it reaches npinfo through the work item via container_of().

Use disable_delayed_work_sync() to ensure the worker is completely stopped and prevent any future re-arming attempts. Once npinfo is set to NULL, senders will bail out and not queue new work. The disable flag ensures any in-flight re-arming attempts also fail silently.

In the future, we can do the cleanup inline here without needing the npinfo->rcu rcu_head, but that is net-next material.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-64424"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-25T10:17:26Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetpoll: fix a use-after-free on shutdown path\n\nThere is a use-after-free error on netpoll, which is clearly detected by\nKASAN.\n\n      BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3b/0x80\n      Read of size 1 at addr ... by task kworker/9:1\n      Workqueue: events queue_process\n      Call Trace:\n       skb_dequeue+0x1e/0xb0\n       queue_process+0x2c/0x600\n       process_scheduled_works+0x4b6/0x850\n       worker_thread+0x414/0x5a0\n      Allocated by task 242:\n       __netpoll_setup+0x201/0x4a0\n       netpoll_setup+0x249/0x550\n       enabled_store+0x32f/0x380\n      Freed by task 0:\n       kfree+0x1b7/0x540\n       rcu_core+0x3f8/0x7a0\n\nThe problem happens when there is a pending TX worker running in\nparallel with the cleanup path.\n\nThis is what happens on netpoll shutdown path:\n\n1) __netpoll_cleanup() is called\n2) set dev-\u003enpinfo to NULL\n3) call_rcu() with rcu_cleanup_netpoll_info()\n  3.1) rcu_cleanup_netpoll_info() tries to cancel all workers with\n       cancel_delayed_work(), but doesn\u0027t wait for the worker to finish\n4) and kfree(npinfo);\n\nBecause 3.1) doesn\u0027t really cancel the work, as the comment says \"we\ncan\u0027t call cancel_delayed_work_sync here, as we are in softirq\", the TX\nworker can run after 4).\n\nTl;DR: queue_process() is not an RCU reader, it reaches npinfo through\nthe work item via container_of().\n\nUse disable_delayed_work_sync() to ensure the worker is completely\nstopped and prevent any future re-arming attempts. Once npinfo is set\nto NULL, senders will bail out and not queue new work. The disable flag\nensures any in-flight re-arming attempts also fail silently.\n\nIn the future, we can do the cleanup inline here without needing the\nnpinfo-\u003ercu rcu_head, but that is net-next material.",
  "id": "GHSA-4m75-5382-c595",
  "modified": "2026-07-25T12:31:35Z",
  "published": "2026-07-25T12:31:35Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64424"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/45f1458a85017a023f138b22ac5c76abd477db42"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5ed09a108d93a3b002cc79823d9455b50c4a8be7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/95ecc5b58042f6b6743b589e6588f1cd7ba336aa"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a33f37f8d079da7236ed7b7e2aed2a34ab81e7cf"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

CVE-2026-64424 (GCVE-0-2026-64424)

GHSA-4M75-5382-C595

Tags

Sightings

Nomenclature