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CVE-2026-63911

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: xfrm: iptfs: reset runtime state when cloning SAs iptfs_clone_state() clones the IPTFS mode data with kmemdup(). This copies runtime objects which must not be shared with the original SA, including the embedded sk_buff_head, hrtimers, spinlock, and in-flight reassembly/reorder state. If xfrm_state_migrate() fails after clone_state() but before the later init_state() call has reinitialized those fields, the cloned state can be destroyed by xfrm_state_gc_task() with list and timer state copied from the original SA. With queued packets this lets the clone splice and free skbs owned by the original IPTFS queue, leading to use-after-free and double-free reports in iptfs_destroy_state() and skb release paths. Reinitialize the clone's runtime state before publishing it through x->mode_data. Because clone_state() now publishes a destroyable mode_data object before init_state(), take the mode callback module reference there. Avoid taking it again from __iptfs_init_state() for the same object.

Severity
HIGH
CVSS score
7.8 (v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-19 16:17:08.987000
Last modified
2026-10-30 14:29:33.557000
View original CVE JSON
{
  "id": "CVE-2026-63911",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-07-19T16:17:08.987",
  "lastModified": "2026-10-30T14:29:33.557",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: reset runtime state when cloning SAs\n\niptfs_clone_state() clones the IPTFS mode data with kmemdup(). This\ncopies runtime objects which must not be shared with the original SA,\nincluding the embedded sk_buff_head, hrtimers, spinlock, and in-flight\nreassembly/reorder state.\n\nIf xfrm_state_migrate() fails after clone_state() but before the later\ninit_state() call has reinitialized those fields, the cloned state can be\ndestroyed by xfrm_state_gc_task() with list and timer state copied from the\noriginal SA. With queued packets this lets the clone splice and free skbs\nowned by the original IPTFS queue, leading to use-after-free and\ndouble-free reports in iptfs_destroy_state() and skb release paths.\n\nReinitialize the clone's runtime state before publishing it through\nx->mode_data. Because clone_state() now publishes a destroyable mode_data\nobject before init_state(), take the mode callback module reference there.\nAvoid taking it again from __iptfs_init_state() for the same object."
    }
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      "affectedData": [
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          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
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      "source": "[email protected]",
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