GHSA-3GC2-W5W2-FFCH
Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:31In 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.
{
"affected": [],
"aliases": [
"CVE-2026-63911"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T16:17:08Z",
"severity": "HIGH"
},
"details": "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\u0027s runtime state before publishing it through\nx-\u003emode_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.",
"id": "GHSA-3gc2-w5w2-ffch",
"modified": "2026-07-20T15:31:50Z",
"published": "2026-07-19T18:31:45Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63911"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7f83d174073234839aea176f265e517e0d50a1d2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9327252e04626d4bb02ca8c0c108fbe8eabf0c5a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dfb9f6cbfa9826655a49698cf90eb800fce2178e"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- 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.