GHSA-F4WG-8884-3QG5
Vulnerability from github – Published: 2026-07-19 12:30 – Updated: 2026-07-24 15:32In the Linux kernel, the following vulnerability has been resolved:
nfsd: release layout stid on setlease failure
nfs4_alloc_stid() publishes the new stid into cl->cl_stateids via idr_alloc_cyclic() under cl_lock before returning to nfsd4_alloc_layout_stateid(). When nfsd4_layout_setlease() then fails, the error path frees the layout stateid directly with kmem_cache_free() without ever calling idr_remove(), leaving the IDR slot pointing at freed slab memory. Any subsequent IDR walker (states_show, client teardown) dereferences the dangling pointer.
The correct teardown for an IDR-published stid is nfs4_put_stid(), which removes the IDR slot under cl_lock, dispatches sc_free (nfsd4_free_layout_stateid) to release ls->ls_file via nfsd4_close_layout(), and drops the nfs4_file reference in its tail.
A second issue blocks that switch: nfsd4_free_layout_stateid() unconditionally inspects ls->ls_fence_work via delayed_work_pending() under ls_lock, but INIT_DELAYED_WORK(&ls->ls_fence_work, ...) currently runs only after the setlease call. On the setlease-failure path the destructor would touch an uninitialized delayed_work.
nfsd4_alloc_layout_stateid()
nfs4_alloc_stid() /* idr_alloc_cyclic under cl_lock */
nfsd4_layout_setlease() /* fails */
nfs4_put_stid()
nfsd4_free_layout_stateid()
delayed_work_pending(&ls->ls_fence_work) /* needs INIT */
nfsd4_close_layout() /* nfsd_file_put(ls->ls_file) */
put_nfs4_file()
Fix by hoisting the ls_fenced / ls_fence_delay / INIT_DELAYED_WORK initialization above the nfsd4_layout_setlease() call, and replace the manual nfsd_file_put + put_nfs4_file + kmem_cache_free cleanup with a single nfs4_put_stid(stp).
{
"affected": [],
"aliases": [
"CVE-2026-53399"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T12:16:51Z",
"severity": "CRITICAL"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: release layout stid on setlease failure\n\nnfs4_alloc_stid() publishes the new stid into cl-\u003ecl_stateids via\nidr_alloc_cyclic() under cl_lock before returning to\nnfsd4_alloc_layout_stateid(). When nfsd4_layout_setlease() then\nfails, the error path frees the layout stateid directly with\nkmem_cache_free() without ever calling idr_remove(), leaving the\nIDR slot pointing at freed slab memory. Any subsequent IDR walker\n(states_show, client teardown) dereferences the dangling pointer.\n\nThe correct teardown for an IDR-published stid is nfs4_put_stid(),\nwhich removes the IDR slot under cl_lock, dispatches sc_free\n(nfsd4_free_layout_stateid) to release ls-\u003els_file via\nnfsd4_close_layout(), and drops the nfs4_file reference in its\ntail.\n\nA second issue blocks that switch: nfsd4_free_layout_stateid()\nunconditionally inspects ls-\u003els_fence_work via\ndelayed_work_pending() under ls_lock, but\nINIT_DELAYED_WORK(\u0026ls-\u003els_fence_work, ...) currently runs only\nafter the setlease call. On the setlease-failure path the\ndestructor would touch an uninitialized delayed_work.\n\n nfsd4_alloc_layout_stateid()\n nfs4_alloc_stid() /* idr_alloc_cyclic under cl_lock */\n nfsd4_layout_setlease() /* fails */\n nfs4_put_stid()\n nfsd4_free_layout_stateid()\n delayed_work_pending(\u0026ls-\u003els_fence_work) /* needs INIT */\n nfsd4_close_layout() /* nfsd_file_put(ls-\u003els_file) */\n put_nfs4_file()\n\nFix by hoisting the ls_fenced / ls_fence_delay / INIT_DELAYED_WORK\ninitialization above the nfsd4_layout_setlease() call, and replace\nthe manual nfsd_file_put + put_nfs4_file + kmem_cache_free cleanup\nwith a single nfs4_put_stid(stp).",
"id": "GHSA-f4wg-8884-3qg5",
"modified": "2026-07-24T15:32:42Z",
"published": "2026-07-19T12:30:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53399"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2e0a5d6d62600b8c614d1b55e50ef94035d6adf9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/30d55c8aabb261bc3f427d6b9aae7ef6206063f9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/48a586e382e4db1dbf958d44b63e081df5f8ed04"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7bbb7ce74051c8be4b69ff44ce3db370600dae61"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/83c2b7797742339bb768f83935f7ca33950db138"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8dee7c278f1c2b5bb80e17a6281c3812fc8b0cdd"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d369e5edfaaf83a448016e2f1da392b2174be801"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d788ef40a7517d22c97ab01700e4ae4c611b6f2f"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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