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FKIE_CVE-2026-80845

Vulnerability from fkie_nvd - Published: 2026-09-04 16:18 - Updated: 2026-09-04 16:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: xfrm: avoid lock inversion in nat keepalive work nat_keepalive_work() walks the state table while xfrm_state_walk() holds net->xfrm.xfrm_state_lock. Its callback then acquires x->lock, which conflicts with the delete path taking the same locks in reverse order via xfrm_state_delete() and __xfrm_state_delete(). This creates an AB-BA deadlock that is reported by lockdep when a NAT keepalive worker races with SA deletion. Fix this by splitting the keepalive walk into two phases. First, collect the candidate states while the walk holds xfrm_state_lock and take a reference on each state. Then, after the walk completes, process each collected state and acquire x->lock without nesting it under xfrm_state_lock.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5c86c895d1cac81a71ead3005084c6265cf6a7a5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/763fe700b7c58ad64fe5202c5638848244dd4127
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/89ef3a2e1e4682ab82b0455ce113f8c39fb9e50d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a9fa05b7a1246797748d15771052639e0d3cabf1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ea09210462316e5235a25eccb11ad0708d86615e
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/xfrm/xfrm_nat_keepalive.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ea09210462316e5235a25eccb11ad0708d86615e",
              "status": "affected",
              "version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae",
              "versionType": "git"
            },
            {
              "lessThan": "5c86c895d1cac81a71ead3005084c6265cf6a7a5",
              "status": "affected",
              "version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae",
              "versionType": "git"
            },
            {
              "lessThan": "89ef3a2e1e4682ab82b0455ce113f8c39fb9e50d",
              "status": "affected",
              "version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae",
              "versionType": "git"
            },
            {
              "lessThan": "a9fa05b7a1246797748d15771052639e0d3cabf1",
              "status": "affected",
              "version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae",
              "versionType": "git"
            },
            {
              "lessThan": "763fe700b7c58ad64fe5202c5638848244dd4127",
              "status": "affected",
              "version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/xfrm/xfrm_nat_keepalive.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.11"
            },
            {
              "lessThan": "6.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.108",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.49",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: avoid lock inversion in nat keepalive work\n\nnat_keepalive_work() walks the state table while xfrm_state_walk()\nholds net-\u003exfrm.xfrm_state_lock. Its callback then acquires x-\u003elock,\nwhich conflicts with the delete path taking the same locks in reverse\norder via xfrm_state_delete() and __xfrm_state_delete(). This creates\nan AB-BA deadlock that is reported by lockdep when a NAT keepalive\nworker races with SA deletion.\n\nFix this by splitting the keepalive walk into two phases. First,\ncollect the candidate states while the walk holds xfrm_state_lock and\ntake a reference on each state. Then, after the walk completes, process\neach collected state and acquire x-\u003elock without nesting it under\nxfrm_state_lock."
    }
  ],
  "id": "CVE-2026-80845",
  "lastModified": "2026-09-04T16:18:13.173",
  "metrics": {},
  "published": "2026-09-04T16:18:13.173",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5c86c895d1cac81a71ead3005084c6265cf6a7a5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/763fe700b7c58ad64fe5202c5638848244dd4127"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/89ef3a2e1e4682ab82b0455ce113f8c39fb9e50d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a9fa05b7a1246797748d15771052639e0d3cabf1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ea09210462316e5235a25eccb11ad0708d86615e"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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