GHSA-CPGX-54RR-4JM6

Vulnerability from github – Published: 2026-05-27 15:33 – Updated: 2026-05-27 15:33
VLAI
Details

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

misc: ibmasm: fix OOB MMIO read in ibmasm_handle_mouse_interrupt()

ibmasm_handle_mouse_interrupt() performs an out-of-bounds MMIO read when the queue reader or writer index from hardware exceeds REMOTE_QUEUE_SIZE (60).

A compromised service processor can trigger this by writing an out-of-range value to the reader or writer MMIO register before asserting an interrupt. Since writer is re-read from hardware on every loop iteration, it can also be set to an out-of-range value after the loop has already started.

The root cause is that get_queue_reader() and get_queue_writer() return raw readl() values that are passed directly into get_queue_entry(), which computes:

queue_begin + reader * sizeof(struct remote_input)

with no bounds check. This unchecked MMIO address is then passed to memcpy_fromio(), reading 8 bytes from unintended device registers. For sufficiently large values the address falls outside the PCI BAR mapping entirely, triggering a machine check exception.

Fix by checking both indices against REMOTE_QUEUE_SIZE at the top of the loop body, before any call to get_queue_entry(). On an out-of-range value, reset the reader register to 0 via set_queue_reader() before breaking, so that normal queue operation can resume if the corrupted hardware state is transient.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-46022"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-27T14:17:20Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmisc: ibmasm: fix OOB MMIO read in ibmasm_handle_mouse_interrupt()\n\nibmasm_handle_mouse_interrupt() performs an out-of-bounds MMIO read\nwhen the queue reader or writer index from hardware exceeds\nREMOTE_QUEUE_SIZE (60).\n\nA compromised service processor can trigger this by writing an\nout-of-range value to the reader or writer MMIO register before\nasserting an interrupt. Since writer is re-read from hardware on\nevery loop iteration, it can also be set to an out-of-range value\nafter the loop has already started.\n\nThe root cause is that get_queue_reader() and get_queue_writer() return\nraw readl() values that are passed directly into get_queue_entry(),\nwhich computes:\n\n  queue_begin + reader * sizeof(struct remote_input)\n\nwith no bounds check. This unchecked MMIO address is then passed to\nmemcpy_fromio(), reading 8 bytes from unintended device registers.\nFor sufficiently large values the address falls outside the PCI BAR\nmapping entirely, triggering a machine check exception.\n\nFix by checking both indices against REMOTE_QUEUE_SIZE at the top of\nthe loop body, before any call to get_queue_entry(). On an out-of-range\nvalue, reset the reader register to 0 via set_queue_reader() before\nbreaking, so that normal queue operation can resume if the corrupted\nhardware state is transient.",
  "id": "GHSA-cpgx-54rr-4jm6",
  "modified": "2026-05-27T15:33:21Z",
  "published": "2026-05-27T15:33:21Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46022"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/07c4f18b303106e6b24492c12b95d48a4b985841"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1ca75f6b74ec7f685464e5745ecfcf3a76d284e9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/22a16d3eafee92a165c756081587c95850127107"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4b6e6ead556734bdc14024c5f837132b1e7a4b84"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fc7e9a74e32299d7e93e178ca482a0b59ef1595b"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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