Linux Kernel up to 6.17.7 guc xe_guc_ct_init use after free

Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 6.17.7. This affects the function xe_guc_ct_init of the component guc. Such manipulation leads to use after free. This vulnerability is referenced as CVE-2025-68193. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.17.7 and classified as critical. Affected by this issue is the function xe_guc_ct_init of the component guc. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: drm/xe/guc: Add devm release action to safely tear down CT When a buffer object (BO) is allocated with the XE_BO_FLAG_GGTT_INVALIDATE flag, the driver initiates TLB invalidation requests via the CTB mechanism while releasing the BO. However a premature release of the CTB BO can lead to system crashes, as observed in: Oops: Oops: 0000 [#1] SMP NOPTI RIP: 0010:h2g_write+0x2f3/0x7c0 [xe] Call Trace: guc_ct_send_locked+0x8b/0x670 [xe] xe_guc_ct_send_locked+0x19/0x60 [xe] send_tlb_invalidation+0xb4/0x460 [xe] xe_gt_tlb_invalidation_ggtt+0x15e/0x2e0 [xe] ggtt_invalidate_gt_tlb.part.0+0x16/0x90 [xe] ggtt_node_remove+0x110/0x140 [xe] xe_ggtt_node_remove+0x40/0xa0 [xe] xe_ggtt_remove_bo+0x87/0x250 [xe] Introduce a devm-managed release action during xe_guc_ct_init() and xe_guc_ct_init_post_hwconfig() to ensure proper CTB disablement before resource deallocation, preventing the use-after-free scenario.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2025-68193 since 12/16/2025. The exploitation is known to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 02/21/2026).

The vulnerability scanner Nessus provides a plugin with the ID 298897 (Ubuntu 25.10 : Linux kernel vulnerabilities (USN-8029-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.17.8 eliminates this vulnerability. Applying the patch 52faa05fcd9f78af99abebe30a4b7b444744c991/ee4b32220a6b41e71512e8804585325e685456ba is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (298897) and CERT Bund (WID-SEC-2025-2868). Once again VulDB remains the best source for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.17.0
• 6.17.1
• 6.17.2
• 6.17.3
• 6.17.4
• 6.17.5
• 6.17.6
• 6.17.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

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