CVE-2021-47494 cfg80211: fix management registrations locking

2024-05-2208:19:42

Linux

www.cve.org

linux kernel

vulnerability

cfg80211

management registrations

locking

list corruption

6.4 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

15.6%

JSON

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

cfg80211: fix management registrations locking

The management registrations locking was broken, the list was
locked for each wdev, but cfg80211_mgmt_registrations_update()
iterated it without holding all the correct spinlocks, causing
list corruption.

Rather than trying to fix it with fine-grained locking, just
move the lock to the wiphy/rdev (still need the list on each
wdev), we already need to hold the wdev lock to change it, so
there’s no contention on the lock in any case. This trivially
fixes the bug since we hold one wdev’s lock already, and now
will hold the lock that protects all lists.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "include/net/cfg80211.h",
      "net/wireless/core.c",
      "net/wireless/core.h",
      "net/wireless/mlme.c"
    ],
    "versions": [
      {
        "version": "6cd536fe62ef",
        "lessThan": "4c22227e39c7",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "6cd536fe62ef",
        "lessThan": "3c897f39b71f",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "6cd536fe62ef",
        "lessThan": "09b1d5dc6ce1",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "include/net/cfg80211.h",
      "net/wireless/core.c",
      "net/wireless/core.h",
      "net/wireless/mlme.c"
    ],
    "versions": [
      {
        "version": "5.8",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.8",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.77",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.14.16",
        "lessThanOrEqual": "5.14.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]