FKIE_CVE-2025-40305

Vulnerability from fkie_nvd - Published: 2025-12-08 01:16 - Updated: 2025-12-08 18:26
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: 9p/trans_fd: p9_fd_request: kick rx thread if EPOLLIN p9_read_work() doesn't set Rworksched and doesn't do schedule_work(m->rq) if list_empty(&m->req_list). However, if the pipe is full, we need to read more data and this used to work prior to commit aaec5a95d59615 ("pipe_read: don't wake up the writer if the pipe is still full"). p9_read_work() does p9_fd_read() -> ... -> anon_pipe_read() which (before the commit above) triggered the unnecessary wakeup. This wakeup calls p9_pollwake() which kicks p9_poll_workfn() -> p9_poll_mux(), p9_poll_mux() will notice EPOLLIN and schedule_work(&m->rq). This no longer happens after the optimization above, change p9_fd_request() to use p9_poll_mux() instead of only checking for EPOLLOUT.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/242531004d7de8c159f9bfadebe33fe8060b1046
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2e1461034aef99e905a1fe5589aaf00eaea73eee
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e8fe3f07a357c39d429e02ca34f740692d88967a
Impacted products
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\n9p/trans_fd: p9_fd_request: kick rx thread if EPOLLIN\n\np9_read_work() doesn\u0027t set Rworksched and doesn\u0027t do schedule_work(m-\u003erq)\nif list_empty(\u0026m-\u003ereq_list).\n\nHowever, if the pipe is full, we need to read more data and this used to\nwork prior to commit aaec5a95d59615 (\"pipe_read: don\u0027t wake up the writer\nif the pipe is still full\").\n\np9_read_work() does p9_fd_read() -\u003e ... -\u003e anon_pipe_read() which (before\nthe commit above) triggered the unnecessary wakeup. This wakeup calls\np9_pollwake() which kicks p9_poll_workfn() -\u003e p9_poll_mux(), p9_poll_mux()\nwill notice EPOLLIN and schedule_work(\u0026m-\u003erq).\n\nThis no longer happens after the optimization above, change p9_fd_request()\nto use p9_poll_mux() instead of only checking for EPOLLOUT."
    }
  ],
  "id": "CVE-2025-40305",
  "lastModified": "2025-12-08T18:26:19.900",
  "metrics": {},
  "published": "2025-12-08T01:16:02.700",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/242531004d7de8c159f9bfadebe33fe8060b1046"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2e1461034aef99e905a1fe5589aaf00eaea73eee"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e8fe3f07a357c39d429e02ca34f740692d88967a"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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