{
  "cveId": "CVE-2022-49767",
  "url": "https://patchblox.com/security/cve/CVE-2022-49767",
  "summary": "CVE-2022-49767 is fixed in linux on 1 platform, first by DEBIAN-CVE-2022-49767, released May 1, 2025. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  9p/trans_fd: always use O_NONBLOCK read/write  s...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  9p/trans_fd: always use O_NONBLOCK read/write  syzbot is reporting hung task at p9_fd_close() [1], for p9_mux_poll_stop()  from p9_conn_destroy() from p9_fd_close() is failing to interrupt already started kernel_read() from p9_fd_read() from p9_read_work() and/or kernel_write() from p9_fd_write() from p9_write_work() requests.  Since p9_socket_open() sets O_NONBLOCK flag, p9_mux_poll_stop() does not need to interrupt kernel_read()/kernel_write(). However, since p9_fd_open() does not set O_NONBLOCK flag, but pipe blocks unless signal is pending, p9_mux_poll_stop() needs to interrupt kernel_read()/kernel_write() when the file descriptor refers to a pipe. In other words, pipe file descriptor needs to be handled as if socket file descriptor.  We somehow need to interrupt kernel_read()/kernel_write() on pipes.  A minimal change, which this patch is doing, is to set O_NONBLOCK flag  from p9_fd_open(), for O_NONBLOCK flag does not affect reading/writing of regular files. But this approach changes O_NONBLOCK flag on userspace- supplied file descriptors (which might break userspace programs), and O_NONBLOCK flag could be changed by userspace. It would be possible to set O_NONBLOCK flag every time p9_fd_read()/p9_fd_write() is invoked, but still remains small race window for clearing O_NONBLOCK flag.  If we don\u0027t want to manipulate O_NONBLOCK flag, we might be able to surround kernel_read()/kernel_write() with set_thread_flag(TIF_SIGPENDING) and recalc_sigpending(). Since p9_read_work()/p9_write_work() works are processed by kernel threads which process global system_wq workqueue, signals could not be delivered from remote threads when p9_mux_poll_stop()  from p9_conn_destroy() from p9_fd_close() is called. Therefore, calling set_thread_flag(TIF_SIGPENDING)/recalc_sigpending() every time would be needed if we count on signals for making kernel_read()/kernel_write() non-blocking.  [Dominique: add comment at Christian\u0027s suggestion]",
  "published": "2025-05-01T15:15:59Z",
  "severity": "medium",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00204,
  "epssPercentile": 0.10408,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.0.10-1",
      "fix": "DEBIAN-CVE-2022-49767",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2022-49767",
      "released": "2025-05-01T15:15:59Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.0.10-1",
      "fix": "DEBIAN-CVE-2022-49767",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2022-49767",
      "released": "2025-05-01T15:15:59Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "6.0.10-1",
      "fix": "DEBIAN-CVE-2022-49767",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2022-49767",
      "released": "2025-05-01T15:15:59Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}