GHSA-C4MH-CV6M-6477

Vulnerability from github – Published: 2024-06-19 15:30 – Updated: 2024-07-03 18:45
VLAI?
Details

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

ALSA: core: Fix NULL module pointer assignment at card init

The commit 81033c6b584b ("ALSA: core: Warn on empty module") introduced a WARN_ON() for a NULL module pointer passed at snd_card object creation, and it also wraps the code around it with '#ifdef MODULE'. This works in most cases, but the devils are always in details. "MODULE" is defined when the target code (i.e. the sound core) is built as a module; but this doesn't mean that the caller is also built-in or not. Namely, when only the sound core is built-in (CONFIG_SND=y) while the driver is a module (CONFIG_SND_USB_AUDIO=m), the passed module pointer is ignored even if it's non-NULL, and card->module remains as NULL. This would result in the missing module reference up/down at the device open/close, leading to a race with the code execution after the module removal.

For addressing the bug, move the assignment of card->module again out of ifdef. The WARN_ON() is still wrapped with ifdef because the module can be really NULL when all sound drivers are built-in.

Note that we keep 'ifdef MODULE' for WARN_ON(), otherwise it would lead to a false-positive NULL module check. Admittedly it won't catch perfectly, i.e. no check is performed when CONFIG_SND=y. But, it's no real problem as it's only for debugging, and the condition is pretty rare.

Severity ?
8.8 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2024-38605"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-06-19T14:15:20Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: core: Fix NULL module pointer assignment at card init\n\nThe commit 81033c6b584b (\"ALSA: core: Warn on empty module\")\nintroduced a WARN_ON() for a NULL module pointer passed at snd_card\nobject creation, and it also wraps the code around it with \u0027#ifdef\nMODULE\u0027.  This works in most cases, but the devils are always in\ndetails.  \"MODULE\" is defined when the target code (i.e. the sound\ncore) is built as a module; but this doesn\u0027t mean that the caller is\nalso built-in or not.  Namely, when only the sound core is built-in\n(CONFIG_SND=y) while the driver is a module (CONFIG_SND_USB_AUDIO=m),\nthe passed module pointer is ignored even if it\u0027s non-NULL, and\ncard-\u003emodule remains as NULL.  This would result in the missing module\nreference up/down at the device open/close, leading to a race with the\ncode execution after the module removal.\n\nFor addressing the bug, move the assignment of card-\u003emodule again out\nof ifdef.  The WARN_ON() is still wrapped with ifdef because the\nmodule can be really NULL when all sound drivers are built-in.\n\nNote that we keep \u0027ifdef MODULE\u0027 for WARN_ON(), otherwise it would\nlead to a false-positive NULL module check.  Admittedly it won\u0027t catch\nperfectly, i.e. no check is performed when CONFIG_SND=y.  But, it\u0027s no\nreal problem as it\u0027s only for debugging, and the condition is pretty\nrare.",
  "id": "GHSA-c4mh-cv6m-6477",
  "modified": "2024-07-03T18:45:57Z",
  "published": "2024-06-19T15:30:54Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-38605"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/39381fe7394e5eafac76e7e9367e7351138a29c1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6b8374ee2cabcf034faa34e69a855dc496a9ec12"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c935e72139e6d523defd60fe875c01eb1f9ea5c5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d7ff29a429b56f04783152ad7bbd7233b740e434"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e007476725730c1a68387b54b7629486d8a8301e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e644036a3e2b2c9b3eee3c61b5d31c2ca8b5ba92"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e7e0ca200772bdb2fdc6d43d32d341e87a36f811"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.