CVE-2024-56549

Source
https://nvd.nist.gov/vuln/detail/CVE-2024-56549
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-56549.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2024-56549
Downstream
Related
Published
2024-12-27T14:15:34Z
Modified
2025-08-09T19:01:28Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

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

cachefiles: Fix NULL pointer dereference in object->file

At present, the object->file has the NULL pointer dereference problem in ondemand-mode. The root cause is that the allocated fd and object->file lifetime are inconsistent, and the user-space invocation to anon_fd uses object->file. Following is the process that triggers the issue:

  [write fd]                [umount]

cachefilesondemandfdwriteiter fscachecookiestatemachine cachefileswithdrawcookie if (!file) return -ENOBUFS cachefilescleanupobject cachefilesunmarkinodeinuse fput(object->file) object->file = NULL // file NULL pointer dereference! _cachefileswrite(..., file, ...)

Fix this issue by add an additional reference count to the object->file before write/llseek, and decrement after it finished.

References

Affected packages