CVE-2024-53133 – Linux Kernel Vulnerability Resolved: drm/amd/display - Handling DML Allocation Failure to Avoid Crash

A significant vulnerability in the Linux kernel has been identified and resolved. This issue, assigned the identifier CVE-2024-53133, pertained to the drm/amd/display and caused crashes in certain instances where dml allocation failed. In this post, we will discuss the root cause, implications, and resolution of this vulnerability while also providing relevant code snippets and links to original references for those interested in further details.

[Why]

The core issue behind this vulnerability was that when a dml (Display Micro-language) allocation failed for any reason, the current state's dml contexts would no longer be valid. As a result, subsequent calls to dc_state_copy_internal would shallow copy invalid memory, and if the new state was released, a double free would occur, ultimately leading to a crash.

[How]

To mitigate this issue and avoid crashes due to dml allocation failure, the vulnerability fix involves resetting the dml pointers in the new_state to NULL and avoiding invalid pointers. The relevant code change has been cherry-picked from commit bcafdc61529a48f6f06355d78eb41b3aeda5296c.

The following snippet highlights the key change made to address this vulnerability

+   // Reset dml pointers in new_state to NULL and avoid invalid pointer
+   new_state->dml.edc_config = NULL;
+   new_state->dml.md_state = NULL;

As shown above, by simply setting the dml pointers in the new_state to NULL, the issue of invalid memory and double frees can be avoided, resolving the vulnerability.

Original References

For those interested in further details and complete information on this vulnerability and its resolution, please refer to the following links:

1. CVE Details – Official CVE page with basic information on the vulnerability.
2. Linux Kernel Commit – Direct link to the kernel commit that resolved this issue.
3. Linux Kernel Mailing List – Discussion thread on LKML that provides additional context and information on this vulnerability.

Conclusion

In summary, the Linux kernel vulnerability CVE-2024-53133 has been successfully resolved through the appropriate handling of dml allocation failures to avoid crashes and improve overall system stability. The fix has been integrated into the kernel and should already be available through regular updates. Linux users are advised to ensure their systems are up to date to benefit from the latest security patches and avoid potential exploits associated with this vulnerability.

Timeline

Published on: 12/04/2024 15:15:13 UTC
Last modified on: 12/11/2024 17:16:16 UTC