ghsa-rg2r-6xmq-h33r
Vulnerability from github
Published
2024-06-19 15:30
Modified
2024-06-19 15:30
Details

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

USB: core: Make do_proc_control() and do_proc_bulk() killable

The USBDEVFS_CONTROL and USBDEVFS_BULK ioctls invoke usb_start_wait_urb(), which contains an uninterruptible wait with a user-specified timeout value. If timeout value is very large and the device being accessed does not respond in a reasonable amount of time, the kernel will complain about "Task X blocked for more than N seconds", as found in testing by syzbot:

INFO: task syz-executor.0:8700 blocked for more than 143 seconds. Not tainted 5.14.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:23192 pid: 8700 ppid: 8455 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0xc07/0x11f0 kernel/sched/core.c:5938 schedule+0x14b/0x210 kernel/sched/core.c:6017 schedule_timeout+0x98/0x2f0 kernel/time/timer.c:1857 do_wait_for_common+0x2da/0x480 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion_timeout+0x46/0x60 kernel/sched/completion.c:157 usb_start_wait_urb+0x167/0x550 drivers/usb/core/message.c:63 do_proc_bulk+0x978/0x1080 drivers/usb/core/devio.c:1236 proc_bulk drivers/usb/core/devio.c:1273 [inline] usbdev_do_ioctl drivers/usb/core/devio.c:2547 [inline] usbdev_ioctl+0x3441/0x6b10 drivers/usb/core/devio.c:2713 ...

To fix this problem, this patch replaces usbfs's calls to usb_control_msg() and usb_bulk_msg() with special-purpose code that does essentially the same thing (as recommended in the comment for usb_start_wait_urb()), except that it always uses a killable wait and it uses GFP_KERNEL rather than GFP_NOIO.

Show details on source website


{
  "affected": [],
  "aliases": [
    "CVE-2021-47582"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-06-19T15:15:52Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: core: Make do_proc_control() and do_proc_bulk() killable\n\nThe USBDEVFS_CONTROL and USBDEVFS_BULK ioctls invoke\nusb_start_wait_urb(), which contains an uninterruptible wait with a\nuser-specified timeout value.  If timeout value is very large and the\ndevice being accessed does not respond in a reasonable amount of time,\nthe kernel will complain about \"Task X blocked for more than N\nseconds\", as found in testing by syzbot:\n\nINFO: task syz-executor.0:8700 blocked for more than 143 seconds.\n      Not tainted 5.14.0-rc7-syzkaller #0\n\"echo 0 \u003e /proc/sys/kernel/hung_task_timeout_secs\" disables this message.\ntask:syz-executor.0  state:D stack:23192 pid: 8700 ppid:  8455 flags:0x00004004\nCall Trace:\n context_switch kernel/sched/core.c:4681 [inline]\n __schedule+0xc07/0x11f0 kernel/sched/core.c:5938\n schedule+0x14b/0x210 kernel/sched/core.c:6017\n schedule_timeout+0x98/0x2f0 kernel/time/timer.c:1857\n do_wait_for_common+0x2da/0x480 kernel/sched/completion.c:85\n __wait_for_common kernel/sched/completion.c:106 [inline]\n wait_for_common kernel/sched/completion.c:117 [inline]\n wait_for_completion_timeout+0x46/0x60 kernel/sched/completion.c:157\n usb_start_wait_urb+0x167/0x550 drivers/usb/core/message.c:63\n do_proc_bulk+0x978/0x1080 drivers/usb/core/devio.c:1236\n proc_bulk drivers/usb/core/devio.c:1273 [inline]\n usbdev_do_ioctl drivers/usb/core/devio.c:2547 [inline]\n usbdev_ioctl+0x3441/0x6b10 drivers/usb/core/devio.c:2713\n...\n\nTo fix this problem, this patch replaces usbfs\u0027s calls to\nusb_control_msg() and usb_bulk_msg() with special-purpose code that\ndoes essentially the same thing (as recommended in the comment for\nusb_start_wait_urb()), except that it always uses a killable wait and\nit uses GFP_KERNEL rather than GFP_NOIO.",
  "id": "GHSA-rg2r-6xmq-h33r",
  "modified": "2024-06-19T15:30:55Z",
  "published": "2024-06-19T15:30:55Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-47582"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/403716741c6c2c510dce44e88f085a740f535de6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ae8709b296d80c7f45aa1f35c0e7659ad69edce1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}


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