GHSA-864F-QFFM-34WC

Vulnerability from github – Published: 2026-05-06 12:30 – Updated: 2026-05-08 15:31
VLAI?
Details

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

atm: fore200e: fix use-after-free in tasklets during device removal

When the PCA-200E or SBA-200E adapter is being detached, the fore200e is deallocated. However, the tx_tasklet or rx_tasklet may still be running or pending, leading to use-after-free bug when the already freed fore200e is accessed again in fore200e_tx_tasklet() or fore200e_rx_tasklet().

One of the race conditions can occur as follows:

CPU 0 (cleanup) | CPU 1 (tasklet) fore200e_pca_remove_one() | fore200e_interrupt() fore200e_shutdown() | tasklet_schedule() kfree(fore200e) | fore200e_tx_tasklet() | fore200e-> // UAF

Fix this by ensuring tx_tasklet or rx_tasklet is properly canceled before the fore200e is released. Add tasklet_kill() in fore200e_shutdown() to synchronize with any pending or running tasklets. Moreover, since fore200e_reset() could prevent further interrupts or data transfers, the tasklet_kill() should be placed after fore200e_reset() to prevent the tasklet from being rescheduled in fore200e_interrupt(). Finally, it only needs to do tasklet_kill() when the fore200e state is greater than or equal to FORE200E_STATE_IRQ, since tasklets are uninitialized in earlier states. In a word, the tasklet_kill() should be placed in the FORE200E_STATE_IRQ branch within the switch...case structure.

This bug was identified through static analysis.

Severity ?
7.5 (High)
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-43203"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-06T12:16:39Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\natm: fore200e: fix use-after-free in tasklets during device removal\n\nWhen the PCA-200E or SBA-200E adapter is being detached, the fore200e\nis deallocated. However, the tx_tasklet or rx_tasklet may still be running\nor pending, leading to use-after-free bug when the already freed fore200e\nis accessed again in fore200e_tx_tasklet() or fore200e_rx_tasklet().\n\nOne of the race conditions can occur as follows:\n\nCPU 0 (cleanup)           | CPU 1 (tasklet)\nfore200e_pca_remove_one() | fore200e_interrupt()\n  fore200e_shutdown()     |   tasklet_schedule()\n    kfree(fore200e)       | fore200e_tx_tasklet()\n                          |   fore200e-\u003e // UAF\n\nFix this by ensuring tx_tasklet or rx_tasklet is properly canceled before\nthe fore200e is released. Add tasklet_kill() in fore200e_shutdown() to\nsynchronize with any pending or running tasklets. Moreover, since\nfore200e_reset() could prevent further interrupts or data transfers,\nthe tasklet_kill() should be placed after fore200e_reset() to prevent\nthe tasklet from being rescheduled in fore200e_interrupt(). Finally,\nit only needs to do tasklet_kill() when the fore200e state is greater\nthan or equal to FORE200E_STATE_IRQ, since tasklets are uninitialized\nin earlier states. In a word, the tasklet_kill() should be placed in\nthe FORE200E_STATE_IRQ branch within the switch...case structure.\n\nThis bug was identified through static analysis.",
  "id": "GHSA-864f-qffm-34wc",
  "modified": "2026-05-08T15:31:17Z",
  "published": "2026-05-06T12:30:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43203"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5189368f10903956be05062d160b2804bf5e5016"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/73fbc5d1a9ccb626937500bbd67136f077d8237b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8930878101cd40063888a68af73b1b0f8b6c79bc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/91f25749aaf57c47ae1e12478144e6ea8c8562f2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/97900f512252a59f23d6ce4ab215cc88fed66e68"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/aba0b4bc09376dfc3d53c826514fe38fc8337f52"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e075ec9b08f862dade8011481058f7eb5f716c57"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e4ff4e3ffcf9d5aad380cdd1d8cdc008bb34f97d"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}


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