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nfsd: convert nfsd_net boolean flags to unsigned long flags word

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: nfsd: convert nfsd_net boolean flags to unsigned long flags word nfsd_net contains several boolean fields that are accessed from concurrent contexts without serialization. In particular, nfsd4_end_grace() guards its drain path with a plain bool: if (nn->grace_ended) return; nn->grace_ended = true; The read and the write are independent, and nothing in struct nfsd_net serializes them. At least two contexts can reach this code with no lock held: laundromat path laundry_wq kworker nfs4_laundromat() nfsd4_end_grace() RECLAIM_COMPLETE path nfsd compound kthread nfsd4_reclaim_complete() inc_reclaim_complete() nfsd4_end_grace() Both callers can observe grace_ended == false on different CPUs, both store true, and both proceed into nfsd4_record_grace_done(), which invokes the active client_tracking_ops->grace_done callback. For tracking ops that drain reclaim_str_hashtbl (legacy_tracking_ops via nfsd4_recdir_purge_old, and the cld v1+ ops via nfsd4_cld_grace_done), grace_done calls nfs4_release_reclaim(), which walks every bucket of reclaim_str_hashtbl with no lock and calls nfs4_remove_reclaim_record() (list_del + kfree) on each entry. Two concurrent walkers corrupt the list and double-free every nfs4_client_reclaim. A concurrent nfsd4_find_reclaim_client() iterating the same bucket reads through freed memory. A third call site exists in nfs4_state_start_net() on the skip_grace startup path, but it runs under nfsd_mu

Announced Source revision 1
Original source ↗

CVE-2026-93221

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-93221

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
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Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "362063a595be959bc08f4163e6405a0266740091",
        "lessThan": "94b450977c60261903c945419d2df4a464de60c4",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "362063a595be959bc08f4163e6405a0266740091",
        "lessThan": "faac245ca739b66e96fb7bb43e21df537239a4e5",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "362063a595be959bc08f4163e6405a0266740091",
        "lessThan": "40bab0da844c142431a6b1cc21b4cf53491dac44",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "362063a595be959bc08f4163e6405a0266740091",
        "lessThan": "df5922fe09a8131c793ffa86adf204999b0470f8",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "362063a595be959bc08f4163e6405a0266740091",
        "lessThan": "11a5fe42e1811f793e04ef885b639ea7668f439d",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "fs/nfsd/netns.h",
      "fs/nfsd/nfs4proc.c",
      "fs/nfsd/nfs4recover.c",
      "fs/nfsd/nfs4state.c",
      "fs/nfsd/nfsctl.c",
      "fs/nfsd/nfssvc.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "5.2"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "5.2",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.6.160",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.114",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.57",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.4",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "fs/nfsd/netns.h",
      "fs/nfsd/nfs4proc.c",
      "fs/nfsd/nfs4recover.c",
      "fs/nfsd/nfs4state.c",
      "fs/nfsd/nfsctl.c",
      "fs/nfsd/nfssvc.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-93221

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#48736 · Revision 1
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Publisher date
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