CVE-2021-47583 media: mxl111sf: change mutex_init() location

2024-06-1914:53:49

Linux

github.com

linux kernel

media

vulnerability

mutex_init()

location

mxl111sf

cve-2021-47583

syzbot

uninitialized mutex

dvb_usbv2_init()

frontend_attach()

AI Score

6.9

Confidence

Low

SSVC

Exploitation

none

Automatable

Technical Impact

partial

JSON

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

media: mxl111sf: change mutex_init() location

Syzbot reported, that mxl111sf_ctrl_msg() uses uninitialized
mutex. The problem was in wrong mutex_init() location.

Previous mutex_init(&state->msg_lock) call was in ->init() function, but
dvb_usbv2_init() has this order of calls:

dvb_usbv2_init()
  dvb_usbv2_adapter_init()
    dvb_usbv2_adapter_frontend_init()
      props-&gt;frontend_attach()

  props-&gt;init()

Since mxl111sf_* devices call mxl111sf_ctrl_msg() in ->frontend_attach()
internally we need to initialize state->msg_lock before
frontend_attach(). To achieve it, ->probe() call added to all mxl111sf_*
devices, which will simply initiaize mutex.

CNA Affected

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "8572211842af",
        "lessThan": "4b2d9600b31f",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "8572211842af",
        "lessThan": "96f182c9f48b",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "8572211842af",
        "lessThan": "b99bdf127af9",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "8572211842af",
        "lessThan": "8c6fdf62bfe1",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "8572211842af",
        "lessThan": "44870a9e7a3c",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "drivers/media/usb/dvb-usb-v2/mxl111sf.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "3.7"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "3.7",
        "versionType": "custom"
      },
      {
        "status": "unaffected",
        "version": "4.19.222",
        "versionType": "custom",
        "lessThanOrEqual": "4.19.*"
      },
      {
        "status": "unaffected",
        "version": "5.4.168",
        "versionType": "custom",
        "lessThanOrEqual": "5.4.*"
      },
      {
        "status": "unaffected",
        "version": "5.10.88",
        "versionType": "custom",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.11",
        "versionType": "custom",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "5.16",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "drivers/media/usb/dvb-usb-v2/mxl111sf.c"
    ],
    "defaultStatus": "affected"
  }
]