GHSA-PFP5-R4VH-W3R6
Vulnerability from github – Published: 2026-04-06 09:31 – Updated: 2026-04-06 09:31In the Linux kernel, the following vulnerability has been resolved:
xfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini()
After cancel_delayed_work_sync() is called from xfrm_nat_keepalive_net_fini(), xfrm_state_fini() flushes remaining states via __xfrm_state_delete(), which calls xfrm_nat_keepalive_state_updated() to re-schedule nat_keepalive_work.
The following is a simple race scenario:
cpu0 cpu1
cleanup_net() [Round 1] ops_undo_list() xfrm_net_exit() xfrm_nat_keepalive_net_fini() cancel_delayed_work_sync(nat_keepalive_work); xfrm_state_fini() xfrm_state_flush() xfrm_state_delete(x) __xfrm_state_delete(x) xfrm_nat_keepalive_state_updated(x) schedule_delayed_work(nat_keepalive_work); rcu_barrier(); net_complete_free(); net_passive_dec(net); llist_add(&net->defer_free_list, &defer_free_list);
cleanup_net() [Round 2] rcu_barrier(); net_complete_free() kmem_cache_free(net_cachep, net); nat_keepalive_work() // on freed net
To prevent this, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync().
{
"affected": [],
"aliases": [
"CVE-2026-31406"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-06T08:16:38Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini()\n\nAfter cancel_delayed_work_sync() is called from\nxfrm_nat_keepalive_net_fini(), xfrm_state_fini() flushes remaining\nstates via __xfrm_state_delete(), which calls\nxfrm_nat_keepalive_state_updated() to re-schedule nat_keepalive_work.\n\nThe following is a simple race scenario:\n\n cpu0 cpu1\n\ncleanup_net() [Round 1]\n ops_undo_list()\n xfrm_net_exit()\n xfrm_nat_keepalive_net_fini()\n cancel_delayed_work_sync(nat_keepalive_work);\n xfrm_state_fini()\n xfrm_state_flush()\n xfrm_state_delete(x)\n __xfrm_state_delete(x)\n xfrm_nat_keepalive_state_updated(x)\n schedule_delayed_work(nat_keepalive_work);\n rcu_barrier();\n net_complete_free();\n net_passive_dec(net);\n llist_add(\u0026net-\u003edefer_free_list, \u0026defer_free_list);\n\ncleanup_net() [Round 2]\n rcu_barrier();\n net_complete_free()\n kmem_cache_free(net_cachep, net);\n nat_keepalive_work()\n // on freed net\n\nTo prevent this, cancel_delayed_work_sync() is replaced with\ndisable_delayed_work_sync().",
"id": "GHSA-pfp5-r4vh-w3r6",
"modified": "2026-04-06T09:31:42Z",
"published": "2026-04-06T09:31:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31406"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/21f2fc49ca6faa393c31da33b8a4e6c41fc84c13"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2255ed6adbc3100d2c4a83abd9d0396d04b87792"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/32d0f44c2f14d60fe8e920e69a28c11051543ec1"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/daf8e3b253aa760ff9e96c7768a464bc1d6b3c90"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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- Confirmed: The vulnerability has been validated from an analyst's perspective.
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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.