GHSA-F6Q7-MJ5X-H2PX
Vulnerability from github – Published: 2026-08-10 15:33 – Updated: 2026-08-14 00:31In the Linux kernel, the following vulnerability has been resolved:
xfrm: clear mode callbacks after failed mode setup
xfrm_state_gc_task can run long after a failed IPTFS state setup. In the reproduced case, __xfrm_init_state() cached x->mode_cbs, IPTFS setup returned -ENOMEM before publishing mode_data, and the temporary module reference from xfrm_get_mode_cbs() was dropped immediately. The dead state then kept x->mode_cbs until deferred GC ran after xfrm_iptfs had been unloaded.
Clear x->mode_cbs when mode init or clone fails before publishing mode_data. Those states never installed mode-specific state or the long-term IPTFS module pin, so deferred GC has nothing mode-specific to destroy and must not retain a callback table pointer past the temporary lookup reference.
The buggy scenario involves two paths, with each column showing the order within that path:
failed setup path: 1. cache x->mode_cbs 2. mode setup fails before mode_data 3. drop the temporary module ref 4. dead state keeps x->mode_cbs cached
GC/unload path: 1. xfrm_state_put() queues GC work 2. xfrm_iptfs unloads later 3. xfrm_state_gc_task runs 4. GC dereferences stale x->mode_cbs
This also covers the failed clone path where clone_state() returns before publishing mode_data.
Validation reproduced this kernel report: Kernel panic - not syncing: Fatal exception CONFIG_FAULT_INJECTION_STACKTRACE_FILTER=y failslab_stacktrace_filter matched xfrm_iptfs frames ack_error=-12 FAULT_INJECTION: forcing a failure BUG: unable to handle page fault Workqueue: events xfrm_state_gc_task RIP: xfrm_state_gc_task+0x142/0x650 Modules linked in: esp4_offload xfrm_user [last unloaded: xfrm_iptfs] Kernel panic - not syncing: Fatal exception
{
"affected": [],
"aliases": [
"CVE-2026-68415"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-10T13:20:35Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: clear mode callbacks after failed mode setup\n\nxfrm_state_gc_task can run long after a failed IPTFS state setup. In the\nreproduced case, __xfrm_init_state() cached x-\u003emode_cbs, IPTFS setup\nreturned -ENOMEM before publishing mode_data, and the temporary module\nreference from xfrm_get_mode_cbs() was dropped immediately. The dead state\nthen kept x-\u003emode_cbs until deferred GC ran after xfrm_iptfs had been\nunloaded.\n\nClear x-\u003emode_cbs when mode init or clone fails before publishing\nmode_data. Those states never installed mode-specific state or the\nlong-term IPTFS module pin, so deferred GC has nothing mode-specific to\ndestroy and must not retain a callback table pointer past the temporary\nlookup reference.\n\nThe buggy scenario involves two paths, with each column showing the order\nwithin that path:\n\nfailed setup path:\n1. cache x-\u003emode_cbs\n2. mode setup fails before mode_data\n3. drop the temporary module ref\n4. dead state keeps x-\u003emode_cbs cached\n\nGC/unload path:\n1. xfrm_state_put() queues GC work\n2. xfrm_iptfs unloads later\n3. xfrm_state_gc_task runs\n4. GC dereferences stale x-\u003emode_cbs\n\nThis also covers the failed clone path where clone_state() returns before\npublishing mode_data.\n\nValidation reproduced this kernel report:\nKernel panic - not syncing: Fatal exception\nCONFIG_FAULT_INJECTION_STACKTRACE_FILTER=y\nfailslab_stacktrace_filter matched xfrm_iptfs frames\nack_error=-12\nFAULT_INJECTION: forcing a failure\nBUG: unable to handle page fault\nWorkqueue: events xfrm_state_gc_task\nRIP: xfrm_state_gc_task+0x142/0x650\nModules linked in: esp4_offload xfrm_user [last unloaded: xfrm_iptfs]\nKernel panic - not syncing: Fatal exception",
"id": "GHSA-f6q7-mj5x-h2px",
"modified": "2026-08-14T00:31:58Z",
"published": "2026-08-10T15:33:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68415"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2538bd3cd1ff5af655908469544ac7b7ae259386"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9845a35986a658816f7752f7ebd7c455a4c7dfdf"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c37a079230128a5237f45fb4e181bc069a5c2955"
}
],
"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
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