{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "bd9d6a3efa9709e653aafbeb859289feccb8e70c"
            },
            {
              "fixed": "48f72aff24f7a7329209dc6cbc27c869f3e3595c"
            },
            {
              "fixed": "6703199f4d7e7f37d6a726a849eb358e8fae72fb"
            },
            {
              "fixed": "19413ccc45070a7270b9e25c2a258daf7f91de42"
            },
            {
              "fixed": "fca26a3fc19ed02278aa2a150af82d43db0302cb"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.109"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.50"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89690.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: defer vfree of compound ops to fix rpc_status UAF\n\nThe rpc_status netlink dumpit walks every in-flight svc_rqst under\nrcu_read_lock and, for NFSv4 requests, reads opnums out of\nargs-\u003eops[]. But args-\u003eops is a separate vmalloc buffer freed\nsynchronously by vfree() in nfsd4_release_compoundargs() at the end\nof every compound. The dumpit's rcu_read_lock pins the svc_rqst\nstruct itself (freed via kfree_rcu), but nothing defers the vfree\nof the ops buffer across the RCU grace period. A concurrent compound\ncompletion can therefore free the buffer while the dumpit is reading\nit — a use-after-free on vmalloc memory.\n\nThe trailing seqcount recheck (smp_load_acquire of rq_status_counter)\ncannot undo a load that already retired against freed memory.\n\nFix by replacing vfree(args-\u003eops) with kvfree_rcu_mightsleep(), which\ndefers the free until after an RCU grace period. This makes the\nexisting rcu_read_lock in the dumpit sufficient to protect the read.\nThe tradeoff is that completed compound ops buffers (up to\n200 * sizeof(struct nfsd4_op)) persist in memory slightly longer,\nacross one grace period, before being reclaimed.",
  "id": "CVE-2026-89690",
  "modified": "2026-09-15T03:30:20.168484905Z",
  "published": "2026-09-11T19:46:10.632Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/19413ccc45070a7270b9e25c2a258daf7f91de42"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/48f72aff24f7a7329209dc6cbc27c869f3e3595c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6703199f4d7e7f37d6a726a849eb358e8fae72fb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fca26a3fc19ed02278aa2a150af82d43db0302cb"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89690.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89690"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "nfsd: defer vfree of compound ops to fix rpc_status UAF"
}