Use After Free Affecting kernel-uek-debug-modules-extra package, versions <0:5.15.0-303.171.5.2.el8uek


Severity

Recommended
0.0
high
0
10

Based on Oracle Linux security rating.

Threat Intelligence

EPSS
0.04% (6th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications

Snyk Learn

Learn about Use After Free vulnerabilities in an interactive lesson.

Start learning
  • Snyk IDSNYK-ORACLE8-KERNELUEKDEBUGMODULESEXTRA-8539334
  • published20 Dec 2024
  • disclosed21 Oct 2024

Introduced: 21 Oct 2024

CVE-2024-49924  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Oracle:8 kernel-uek-debug-modules-extra to version 0:5.15.0-303.171.5.2.el8uek or higher.
This issue was patched in ELSA-2024-12887.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-uek-debug-modules-extra package and not the kernel-uek-debug-modules-extra package as distributed by Oracle. See How to fix? for Oracle:8 relevant fixed versions and status.

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

fbdev: pxafb: Fix possible use after free in pxafb_task()

In the pxafb_probe function, it calls the pxafb_init_fbinfo function, after which &fbi->task is associated with pxafb_task. Moreover, within this pxafb_init_fbinfo function, the pxafb_blank function within the &pxafb_ops struct is capable of scheduling work.

If we remove the module which will call pxafb_remove to make cleanup, it will call unregister_framebuffer function which can call do_unregister_framebuffer to free fbi->fb through put_fb_info(fb_info), while the work mentioned above will be used. The sequence of operations that may lead to a UAF bug is as follows:

CPU0 CPU1

                               | pxafb_task

pxafb_remove | unregister_framebuffer(info) | do_unregister_framebuffer(fb_info) | put_fb_info(fb_info) | // free fbi->fb | set_ctrlr_state(fbi, state) | __pxafb_lcd_power(fbi, 0) | fbi->lcd_power(on, &fbi->fb.var) | //use fbi->fb

Fix it by ensuring that the work is canceled before proceeding with the cleanup in pxafb_remove.

Note that only root user can remove the driver at runtime.

CVSS Scores

version 3.1