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FKIE_CVE-2026-31579

Vulnerability from fkie_nvd - Published: 2026-04-24 15:16 - Updated: 2026-06-17 10:34
Severity
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: wireguard: device: use exit_rtnl callback instead of manual rtnl_lock in pre_exit wg_netns_pre_exit() manually acquires rtnl_lock() inside the pernet .pre_exit callback. This causes a hung task when another thread holds rtnl_mutex - the cleanup_net workqueue (or the setup_net failure rollback path) blocks indefinitely in wg_netns_pre_exit() waiting to acquire the lock. Convert to .exit_rtnl, introduced in commit 7a60d91c690b ("net: Add ->exit_rtnl() hook to struct pernet_operations."), where the framework already holds RTNL and batches all callbacks under a single rtnl_lock()/rtnl_unlock() pair, eliminating the contention window. The rcu_assign_pointer(wg->creating_net, NULL) is safe to move from .pre_exit to .exit_rtnl (which runs after synchronize_rcu()) because all RCU readers of creating_net either use maybe_get_net() - which returns NULL for a dying namespace with zero refcount - or access net->user_ns which remains valid throughout the entire ops_undo_list sequence. [ Jason: added __net_exit and __read_mostly annotations that were missing. ]
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1c52ef00e391144334f10995985c2f256d4be982Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/60a25ef8dacb3566b1a8c4de00572a498e2a3bf9Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9a9e69155b2091b8297afaf1533b8d68a3096841Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a1d0f6cbb962af29586e3e65a4bced1a5e39221fPatch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/wireguard/device.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "900575aa33a3eaaef802b31de187a85c4a4b4bd0",
              "versionType": "git"
            },
            {
              "lessThan": "1c52ef00e391144334f10995985c2f256d4be982",
              "status": "affected",
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              "versionType": "git"
            },
            {
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              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "60a25ef8dacb3566b1a8c4de00572a498e2a3bf9",
              "status": "affected",
              "version": "900575aa33a3eaaef802b31de187a85c4a4b4bd0",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "363cc6efdbb54bb06cd5034a69b41aae974a736f",
              "versionType": "git"
            },
            {
              "lessThan": "5.8",
              "status": "affected",
              "version": "5.7.7",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/wireguard/device.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.8"
            },
            {
              "lessThan": "5.8",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.24",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.1",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "E7BFA239-2F39-4B24-92AA-6F60AA187C18",
              "versionEndExcluding": "6.18.24",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "D6A8A074-BBF4-4803-ABED-519A839435BB",
              "versionEndExcluding": "6.19.14",
              "versionStartIncluding": "6.19",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "9B5888AB-7403-4335-89E4-21CC0B48366A",
              "versionEndExcluding": "7.0.1",
              "versionStartIncluding": "7.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwireguard: device: use exit_rtnl callback instead of manual rtnl_lock in pre_exit\n\nwg_netns_pre_exit() manually acquires rtnl_lock() inside the\npernet .pre_exit callback.  This causes a hung task when another\nthread holds rtnl_mutex - the cleanup_net workqueue (or the\nsetup_net failure rollback path) blocks indefinitely in\nwg_netns_pre_exit() waiting to acquire the lock.\n\nConvert to .exit_rtnl, introduced in commit 7a60d91c690b (\"net:\nAdd -\u003eexit_rtnl() hook to struct pernet_operations.\"), where the\nframework already holds RTNL and batches all callbacks under a\nsingle rtnl_lock()/rtnl_unlock() pair, eliminating the contention\nwindow.\n\nThe rcu_assign_pointer(wg-\u003ecreating_net, NULL) is safe to move\nfrom .pre_exit to .exit_rtnl (which runs after synchronize_rcu())\nbecause all RCU readers of creating_net either use maybe_get_net()\n- which returns NULL for a dying namespace with zero refcount - or\naccess net-\u003euser_ns which remains valid throughout the entire\nops_undo_list sequence.\n\n[ Jason: added __net_exit and __read_mostly annotations that were missing. ]"
    }
  ],
  "id": "CVE-2026-31579",
  "lastModified": "2026-06-17T10:34:01.017",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-04-24T15:16:32.587",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/1c52ef00e391144334f10995985c2f256d4be982"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/60a25ef8dacb3566b1a8c4de00572a498e2a3bf9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/9a9e69155b2091b8297afaf1533b8d68a3096841"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/a1d0f6cbb962af29586e3e65a4bced1a5e39221f"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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