GHSA-6VG3-7HP6-MQC5

Vulnerability from github – Published: 2026-07-27 09:31 – Updated: 2026-07-30 06:32
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path

In nvmet_tcp_try_recv_ddgst(), when a data digest mismatch is detected, nvmet_req_uninit() is called unconditionally. However, if the command arrived via the nvmet_tcp_handle_req_failure() path, nvmet_req_init() had returned false and percpu_ref_tryget_live() was never executed. The unconditional percpu_ref_put() inside nvmet_req_uninit() then causes a refcount underflow, leading to a WARNING in percpu_ref_switch_to_atomic_rcu, a use-after-free diagnostic, and eventually a permanent workqueue deadlock.

Check cmd->flags & NVMET_TCP_F_INIT_FAILED before calling nvmet_req_uninit(), matching the existing pattern in nvmet_tcp_execute_request().

Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-64534"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-27T08:16:22Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path\n\nIn nvmet_tcp_try_recv_ddgst(), when a data digest mismatch is detected,\nnvmet_req_uninit() is called unconditionally. However, if the command\narrived via the nvmet_tcp_handle_req_failure() path, nvmet_req_init()\nhad returned false and percpu_ref_tryget_live() was never executed. The\nunconditional percpu_ref_put() inside nvmet_req_uninit() then causes a\nrefcount underflow, leading to a WARNING in\npercpu_ref_switch_to_atomic_rcu, a use-after-free diagnostic, and\neventually a permanent workqueue deadlock.\n\nCheck cmd-\u003eflags \u0026 NVMET_TCP_F_INIT_FAILED before calling\nnvmet_req_uninit(), matching the existing pattern in\nnvmet_tcp_execute_request().",
  "id": "GHSA-6vg3-7hp6-mqc5",
  "modified": "2026-07-30T06:32:32Z",
  "published": "2026-07-27T09:31:26Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64534"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2ed3c9d955e8cd6361f130623baa664a75fb345f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4606467a75cfc16721937272ed29462a750b60c8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c7874dad84b20433c0fe3919f291a762d40de08b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d306da8833e75f669d93424fd84940236f3850bc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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