CVE-2026-97519 in Linux
Summary
by MITRE • 09/24/2026
In the Linux kernel, the following vulnerability has been resolved:
drm/xe: Fix null pointer dereference in devcoredump cleanup
In xe_devcoredump_snapshot_free(), ss->gt may be NULL when the snapshot was never fully populated (e.g., when cleanup is triggered without a prior capture). Guard the xe_guc_capture_put_matched_nodes() call with IS_ERR_OR_NULL() to prevent a null dereference.
In xe_devcoredump_free(), the deferred work is only queued when a coredump is captured, so guard cancel_work_sync() with a check on coredump->captured.
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Analysis
by VulDB Data Team • 09/24/2026
The Linux kernel's DRM Xe driver contains a critical flaw in its devcoredump cleanup logic that can lead to null pointer dereferences during error handling or incomplete capture scenarios. This vulnerability arises from insufficient validation of internal state variables before accessing them, specifically within the functions xe_devcoredump_snapshot_free and xe_devcoredump_free. The core issue stems from assumptions about the initialization status of snapshot structures when cleanup routines are invoked without a prior successful data capture event.
In the function xe_devcoredump_snapshot_free, the code attempts to access the gt member of the ss structure by passing it to xe_guc_capture_put_matched_nodes. However, if the devcoredump snapshot was never fully populated due to an early failure or aborted operation, this pointer remains NULL. Dereferencing a null pointer in kernel space typically results in a page fault that crashes the entire system, leading to a denial of service condition for all users and processes on the affected machine. To mitigate this risk, the fix introduces a guard using IS_ERR_OR_NULL macro checks before invoking xe_guc_capture_put_matched_nodes. This ensures that operations are only performed when valid pointers exist, thereby preventing illegal memory access attempts during cleanup phases where state integrity cannot be guaranteed.
A similar logical gap exists in xe_devcoredump_free regarding deferred work management. The kernel's devcoredump subsystem queues a work item for asynchronous processing only after a coredump has been successfully captured and populated with data. However, the original implementation did not verify whether this capture actually occurred before attempting to cancel the pending work via cancel_work_sync. If cleanup is triggered without an active or completed capture, calling cancel_work_sync on uninitialized or irrelevant state can lead to undefined behavior or crashes due to accessing invalid memory regions associated with non-existent work structures. The resolution involves adding a conditional check on coredump->captured before executing cancel_work_sync, ensuring that synchronization operations are only applied when there is actual deferred work present in the system queue.
From a vulnerability classification perspective, this issue aligns with CWE-476, which denotes NULL Pointer Dereference vulnerabilities. These flaws occur when software fails to check for null values before using pointers, often resulting in application crashes or potential code execution if an attacker can influence the state leading to such dereferences. In the context of kernel development, while direct remote exploitation is less common than user-space applications, local privilege escalation remains a theoretical risk if other memory corruption primitives are present alongside this flaw. Furthermore, from a behavioral standpoint related to MITRE ATT&CK frameworks, this vulnerability falls under Defense Evasion techniques where attackers might trigger specific error paths or race conditions to cause system instability as part of broader disruption campaigns against critical infrastructure components like graphics subsystems in Linux environments.
The operational impact of these vulnerabilities is primarily centered around system stability and availability. A successful exploitation would manifest as a kernel panic, requiring an immediate reboot of the host machine. For systems running headless servers or cloud instances without automatic restart capabilities, this results in significant downtime and potential data loss if uncommitted transactions are involved. Additionally, frequent crashes due to such bugs can degrade overall system performance by consuming resources on crash dumps and recovery processes.
Mitigation strategies involve applying the upstream kernel patches that address these specific null pointer checks immediately after they become available through official distribution channels. System administrators should monitor for updates related to drm/xe components in their respective Linux distributions. For environments where immediate patching is not feasible, reducing exposure by disabling unnecessary GPU features or limiting access to graphics-intensive workloads can lower the attack surface until a permanent fix is deployed. Regular auditing of kernel logs for oops messages or stack traces pointing to devcoredump functions can also help identify instances where these vulnerabilities are being triggered in real-world scenarios, allowing for proactive intervention before catastrophic failures occur.