CVE-2026-72342: Software Security Vulnerability Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-q42x-cp58-jpg7",
  "modified" : "2026-08-17T06:33:24Z",
  "published" : "2026-08-15T06:32:21Z",
  "aliases" : [ "CVE-2026-72342" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix HV VHCA stats agent registration race\n\nmlx5e_hv_vhca_stats_create() registers the stats agent through\nmlx5_hv_vhca_agent_create(). The helper publishes the agent in\nhv_vhca->agents[type] under agents_lock and immediately schedules an\nasynchronous control invalidation on the HV VHCA workqueue before\nreturning to mlx5e.\n\nThe asynchronous invalidation invokes the control agent's invalidate\ncallback, which reads the hypervisor control block and forwards the\ncommand to mlx5e_hv_vhca_stats_control(). That callback may either:\n\n  - call cancel_delayed_work_sync(&priv->stats_agent.work), or\n  - call queue_delayed_work(priv->wq, &sagent->work, sagent->delay).\n\nHowever, the delayed_work and priv->stats_agent.agent are only\ninitialized after mlx5_hv_vhca_agent_create() returns to mlx5e:\n\n    agent = mlx5_hv_vhca_agent_create(...);   /* publish + invalidate */\n    ...\n    priv->stats_agent.agent = agent;          /* too late */\n    INIT_DELAYED_WORK(&priv->stats_agent.work, ...); /* too late */\n\nIf the asynchronous control path runs before the two assignments\nabove, it can:\n\n  - Operate on an uninitialized delayed_work whose timer.function is\n    NULL. queue_delayed_work() calls add_timer() unconditionally, so\n    when the timer expires the timer softirq invokes a NULL function\n    pointer.\n  - Re-initialize the timer later through INIT_DELAYED_WORK() while\n    the timer is already enqueued in the timer wheel, corrupting the\n    hlist (entry.pprev cleared while the previous bucket node still\n    points at this entry).\n  - When the worker eventually runs, mlx5e_hv_vhca_stats_work() reads\n    sagent->agent (NULL) and dereferences it inside\n    mlx5_hv_vhca_agent_write().\n\nFix this by:\n\n  - Initializing priv->stats_agent.work before invoking\n    mlx5_hv_vhca_agent_create(), so the work is always in a valid\n    state when the control callback observes it.\n  - Adding a struct mlx5_hv_vhca_agent **ctx_update out-parameter\n    to mlx5_hv_vhca_agent_create(). The helper writes the agent\n    pointer to *ctx_update before publishing into hv_vhca->agents[]\n    and triggering the agents_update flow, so any callback\n    subsequently invoked from that flow already sees a valid\n    priv->stats_agent.agent. This avoids having the control\n    callback participate in agent initialization.\n\nWhile at it, access priv->stats_agent.agent with\nREAD_ONCE()/WRITE_ONCE() for the cross-CPU access with the worker, and\nclear priv->stats_agent.buf on the agent_create() failure path.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-72342"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/24c77044cdfcf5b8b2e9f3b620d8b9aa392d9add"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/60fddda7207d81fea71463abd403f0b10f74f2e1"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/89b25b5f46f488ea3b29b3444864c76944c9075b"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/b0fd6d3bb06182f19f3b59a53f57b5098b99048a"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/e8fc3304cb67fb1d7d11ff9ef9abd5fb64e7e1d5"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/f5677797b094c3ec5fb350eb8ea7710b88a3d018"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-15T06:22:07Z"
  }
}