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CVE-2026-31516

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: xfrm: prevent policy_hthresh.work from racing with netns teardown A XFRM_MSG_NEWSPDINFO request can queue the per-net work item policy_hthresh.work onto the system workqueue. The queued callback, xfrm_hash_rebuild(), retrieves the enclosing struct net via container_of(). If the net namespace is torn down before that work runs, the associated struct net may already have been freed, and xfrm_hash_rebuild() may then dereference stale memory. xfrm_policy_fini() already flushes policy_hash_work during teardown, but it does not synchronize policy_hthresh.work. Synchronize policy_hthresh.work in xfrm_policy_fini() as well, so the queued work cannot outlive the net namespace teardown and access a freed struct net.

Severity
HIGH
CVSS score
7.8 (v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-04-22 14:16:51.130000
Last modified
2026-10-19 19:17:58.573000
View original CVE JSON 
{
  "id": "CVE-2026-31516",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-04-22T14:16:51.130",
  "lastModified": "2026-10-19T19:17:58.573",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: prevent policy_hthresh.work from racing with netns teardown\n\nA XFRM_MSG_NEWSPDINFO request can queue the per-net work item\npolicy_hthresh.work onto the system workqueue.\n\nThe queued callback, xfrm_hash_rebuild(), retrieves the enclosing\nstruct net via container_of(). If the net namespace is torn down\nbefore that work runs, the associated struct net may already have\nbeen freed, and xfrm_hash_rebuild() may then dereference stale memory.\n\nxfrm_policy_fini() already flushes policy_hash_work during teardown,\nbut it does not synchronize policy_hthresh.work.\n\nSynchronize policy_hthresh.work in xfrm_policy_fini() as well, so the\nqueued work cannot outlive the net namespace teardown and access a\nfreed struct net."
    }
  ],
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          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
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}