{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  sunrpc: init gssp_lock before publishing proc entry  create_use_gss_proxy_proc_entry() publishes /proc/net/rpc/use-gss-proxy via proc_create_data() before init_gssp_clnt() runs mutex_init() on sn-\u003egssp_lock.  Once the dentry is linked under proc_subdir_lock it is immediately reachable from userspace, so a write that lands in the window drives set_gssp_clnt() into mutex_lock() on a zero-initialized struct mutex.      create_use_gss_proxy_proc_entry(net)       proc_create_data(\"use-gss-proxy\", ...)   /* dentry live */       init_gssp_clnt(sn)         mutex_init(\u0026sn-\u003egssp_lock)             /* too late */      write_gssp()       set_gssp_clnt(net)         mutex_lock(\u0026sn-\u003egssp_lock)             /* uninitialized */         gssp_rpc_create(...)         sn-\u003egssp_clnt = clnt         mutex_unlock(\u0026sn-\u003egssp_lock)  The window spans only the two statements between proc_create_data() returning and init_gssp_clnt(), so a writer reaches it only if the registering thread is preempted there while another task is already opening the freshly published file.  register_pernet_subsys() runs in preemptible context under pernet_ops_rwsem, so that preemption is possible, and the window widens on auth_rpcgss module load, when the proc entry is created for every live net namespace whose tasks are already running.  A writer that wins the race locks a zero-filled struct mutex.  On CONFIG_DEBUG_MUTEXES the missing magic value trips a \"lock used without init\" splat; on a production kernel the fast path acquires the lock via CMPXCHG(owner, 0, current).  In the latter case a second writer that arrives before init_gssp_clnt() re-zeroes owner can enter set_gssp_clnt() concurrently, shut down the first writer's clnt while it is still in use, and leak the loser's clnt.  Fix by initializing sn-\u003egssp_lock in sunrpc_init_net() so its lifetime matches the sunrpc_net it lives in.  sn-\u003egssp_clnt is already NULL from the kzalloc that backs net_generic storage, so the lazy helper is no longer needed; drop init_gssp_clnt(), its prototype, and the call from create_use_gss_proxy_proc_entry().  sunrpc.ko is a build-time dependency of auth_rpcgss.ko, so sunrpc_init_net() has always run on every netns before any auth_gss pernet init can publish the proc entry.",
  "id": "DEBIAN-CVE-2026-89540",
  "modified": "2026-09-15T08:47:33.207569669Z",
  "published": "2026-09-11T20:19:37.097Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-89540"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-89540"
  ]
}