CVE-2024-27043 - Critical Use-After-Free Vulnerability Resolved in Linux Kernel Media Subsystem

A critical security vulnerability, identified as CVE-2024-27043, has been fixed in the Linux kernel. This vulnerability could potentially allow attackers to execute arbitrary code or crash vulnerable systems. The vulnerability is caused by a use-after-free issue in the media subsystem of Linux, specifically within the dvbdev component.

The patch for the vulnerability has been released, and administrators are urged to apply the patch immediately to vulnerable systems.

Details

The vulnerability exists in the dvb_register_device function, with the use-after-free occurring as a result of _*pdvbdev_ being set equal to _dvbdev_, which is freed in some error-handling paths. However, _*pdvbdev_ is not set to NULL after the deallocation of _dvbdev_, leading to use-after-frees at various points.

An example of this behavior is shown in the following call chain

budget_register
  |-> dvb_dmxdev_init
        |-> dvb_register_device
  |-> dvb_dmxdev_release
        |-> dvb_unregister_device
              |-> dvb_remove_device
                    |-> dvb_device_put
                          |-> kref_put

In this case, when calling the function _dvb_unregister_device_, there's a possibility that _dmxdev->dvbdev_ (i.e., _*pdvbdev_ in _dvb_register_device_) could point to memory that had been freed earlier in the _dvb_register_device_. This pointer is subsequently passed to _kref_put_, triggering a use-after-free.

Impact

An attacker able to trigger this use-after-free vulnerability could potentially execute arbitrary code, crash the system, or cause other undefined behavior.

Solution

The vulnerability has been fixed in the latest Linux kernel updates. Administrators are recommended to apply security updates as soon as possible to mitigate the risk of exploitation.

Original References

For further details on the vulnerability, the patch, and the technical aspects behind the issue, refer to the following references:

1. Linux Kernel Mailing List: "media: dvbdev: fix a use-after-free"
2. Linux Git Repository: "commit 440cd49a847a96630f5c3e28393409449517ba9"

Conclusion

CVE-2024-27043 highlights a critical use-after-free vulnerability in the Linux kernel, specifically within the media subsystem's dvbdev component. Administrators are urged to apply the patch as soon as possible to keep their systems secure. By staying current with security updates, you can minimize the risk of exploitation and ensure that your systems remain protected.

Timeline

Published on: 05/01/2024 13:15:49 UTC
Last modified on: 12/23/2024 19:13:31 UTC