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sunrpc: wait for in-flight TLS handshake callback when cancel loses race

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: sunrpc: wait for in-flight TLS handshake callback when cancel loses race When wait_for_completion_interruptible_timeout() in svc_tcp_handshake() returns 0 (timeout) or -ERESTARTSYS (signal) and tls_handshake_cancel() then returns false, handshake_complete() has won the cancellation race: it has set HANDSHAKE_F_REQ_COMPLETED and is about to invoke svc_tcp_handshake_done(), but the callback's side effects on xpt_flags and on svsk->sk_handshake_done have not yet committed. The current code reads xpt_flags immediately to decide whether the session succeeded. Two races result. If the callback has executed set_bit(XPT_TLS_SESSION) but not yet clear_bit(XPT_HANDSHAKE), svc_tcp_handshake() sees a session, enqueues the transport, and returns. svc_xprt_received() then clears XPT_BUSY, a worker thread picks the transport up, the dispatcher in svc_handle_xprt() observes XPT_HANDSHAKE still set, and xpo_handshake is invoked a second time. That svc_tcp_handshake() calls init_completion(&svsk->sk_handshake_done) while the original callback concurrently calls complete_all() on it, corrupting the embedded swait_queue. If the callback has set HANDSHAKE_F_REQ_COMPLETED but not yet entered svc_tcp_handshake_done(), svc_tcp_handshake() reads XPT_TLS_SESSION as clear and tears the connection down even though the handshake is about to succeed. Wait for the callback to commit before inspecting xpt_flags. The completion is guaranteed

Announced Source revision 1
Original source ↗

CVE-2026-72221

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-2026-72221

Linux

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

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

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": "b3cbf98e2fdf3cb147a95161560cd25987284330",
        "lessThan": "0d8ceb39884148dc7a2fdf71e1cac5961ed1d2b9",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b3cbf98e2fdf3cb147a95161560cd25987284330",
        "lessThan": "e0f4691d42a54d359d8b64509fd9ab938d4f2a33",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b3cbf98e2fdf3cb147a95161560cd25987284330",
        "lessThan": "65b23bec1fca6e9ebdc3e6041ebf8c6ab074141b",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b3cbf98e2fdf3cb147a95161560cd25987284330",
        "lessThan": "a4f878e8ecd729ccf2e50993444e217583adeace",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b3cbf98e2fdf3cb147a95161560cd25987284330",
        "lessThan": "d00e32f84ca1a77cb67a3fbf59f58dada95f5a21",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "net/sunrpc/svcsock.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "6.4"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "6.4",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.6.145",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.97",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.40",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.1.5",
        "versionType": "semver",
        "lessThanOrEqual": "7.1.*"
      },
      {
        "status": "unaffected",
        "version": "7.2",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "net/sunrpc/svcsock.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-72221

Source reference: /cveMetadata/cveId

Publisher severity

critical

Source reference: /containers/cna/metrics

Event
#32974 · Revision 1
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Publisher date
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