FKIE_CVE-2026-89715

Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-10-19 09:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: NFS/localio: fix ref leak on nfs_uuid_add_file failure When nfs_uuid_add_file() races with nfs_uuid_put() tearing down uuid->net, it returns -ENXIO without publishing nfl->nfs_uuid via rcu_assign_pointer(). nfs_open_local_fh() then enters its error branch and only releases the slot's file ref and its paired net ref plus its own entry-time net ref, while the close path is a no-op: nfs_close_local_fh() nfs_uuid = rcu_dereference(nfl->nfs_uuid); if (!nfs_uuid) { rcu_read_unlock(); return; } /* always */ nfsd_open_local_fh() returns localio holding a caller-owned +1 nfsd_file reference (from nfsd_file_get() after nfsd_file_acquire_local()) and an entry-time nfsd_net reference (from its first nfsd_net_try_get()) embedded as nf->nf_net. Both are leaked on the failure path, pinning one nfsd_file (and the underlying struct file, dentry, inode) and one nfsd_net_ref per occurrence, which blocks nfsd_net and netns teardown. Fix by releasing the caller-owned file ref and its net ref through the existing helper, using a stack-local RCU pointer so the helper can xchg it out, then returning -ENXIO so callers do not dereference a localio whose slot has been cleared: struct nfsd_file __rcu *tmp = RCU_INITIALIZER(localio); nfs_to_nfsd_file_put_local(pnf); nfs_to_nfsd_file_put_local(&tmp); localio = ERR_PTR(-ENXIO); The trailing nfs_to_nfsd_net_put(net) continues to release the outer net ref, so all three nfsd_net_try_get() increments are balanced on the error branch.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5215e734bf7cba18237155f8cb2a0accb60ca339
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9f59b05423ed381f8cdeaaae4bd6778adcb6865c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ca018c19e0ba38975e5ddc3ef8117d5b734313aa
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/nfs_common/nfslocalio.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5215e734bf7cba18237155f8cb2a0accb60ca339",
              "status": "affected",
              "version": "fdd015de767977f21892329af5e12276eb80375f",
              "versionType": "git"
            },
            {
              "lessThan": "9f59b05423ed381f8cdeaaae4bd6778adcb6865c",
              "status": "affected",
              "version": "fdd015de767977f21892329af5e12276eb80375f",
              "versionType": "git"
            },
            {
              "lessThan": "ca018c19e0ba38975e5ddc3ef8117d5b734313aa",
              "status": "affected",
              "version": "fdd015de767977f21892329af5e12276eb80375f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "55735dc5a0ee0c0fc14cb51e005eae862906a410",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "7cac8a129fc53497f9ee5d66fca55a245d009b97",
              "versionType": "git"
            },
            {
              "lessThan": "6.16",
              "status": "affected",
              "version": "6.15.10",
              "versionType": "semver"
            },
            {
              "lessThan": "6.17",
              "status": "affected",
              "version": "6.16.1",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/nfs_common/nfslocalio.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.17"
            },
            {
              "lessThan": "6.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFS/localio: fix ref leak on nfs_uuid_add_file failure\n\nWhen nfs_uuid_add_file() races with nfs_uuid_put() tearing down\nuuid-\u003enet, it returns -ENXIO without publishing nfl-\u003enfs_uuid via\nrcu_assign_pointer().  nfs_open_local_fh() then enters its error\nbranch and only releases the slot\u0027s file ref and its paired net\nref plus its own entry-time net ref, while the close path is a\nno-op:\n\n    nfs_close_local_fh()\n      nfs_uuid = rcu_dereference(nfl-\u003enfs_uuid);\n      if (!nfs_uuid) { rcu_read_unlock(); return; }  /* always */\n\nnfsd_open_local_fh() returns localio holding a caller-owned +1\nnfsd_file reference (from nfsd_file_get() after\nnfsd_file_acquire_local()) and an entry-time nfsd_net reference\n(from its first nfsd_net_try_get()) embedded as nf-\u003enf_net.  Both\nare leaked on the failure path, pinning one nfsd_file (and the\nunderlying struct file, dentry, inode) and one nfsd_net_ref per\noccurrence, which blocks nfsd_net and netns teardown.\n\nFix by releasing the caller-owned file ref and its net ref through\nthe existing helper, using a stack-local RCU pointer so the helper\ncan xchg it out, then returning -ENXIO so callers do not\ndereference a localio whose slot has been cleared:\n\n    struct nfsd_file __rcu *tmp = RCU_INITIALIZER(localio);\n\n    nfs_to_nfsd_file_put_local(pnf);\n    nfs_to_nfsd_file_put_local(\u0026tmp);\n    localio = ERR_PTR(-ENXIO);\n\nThe trailing nfs_to_nfsd_net_put(net) continues to release the\nouter net ref, so all three nfsd_net_try_get() increments are\nbalanced on the error branch."
    }
  ],
  "id": "CVE-2026-89715",
  "lastModified": "2026-10-19T09:18:10.470",
  "metrics": {},
  "published": "2026-09-11T20:19:58.993",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5215e734bf7cba18237155f8cb2a0accb60ca339"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9f59b05423ed381f8cdeaaae4bd6778adcb6865c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ca018c19e0ba38975e5ddc3ef8117d5b734313aa"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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