CVE-2026-72097 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
dm-verity: fix a possible NULL pointer dereference
Fix a possible NULL pointer dereference dm_verity_loadpin_is_bdev_trusted if the device has no table.
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Analysis
by VulDB Data Team • 08/15/2026
The vulnerability identified in the Linux kernel relates to a potential null pointer dereference within the device mapper verity subsystem, specifically in the dm_verity_loadpin_is_bdev_trusted function. This issue occurs when a device lacks an associated table structure, creating a scenario where the code attempts to access memory through a null pointer reference. The device mapper verity implementation is designed to provide transparent integrity verification for block devices, enabling systems to ensure data consistency and detect tampering through cryptographic checksums. When a device is initialized without proper table configuration, the function fails to validate the existence of the required table structure before attempting to dereference it, leading to a kernel panic or system crash.
This vulnerability represents a classic null pointer dereference flaw that can be exploited to cause denial of service conditions within the Linux kernel. The technical implementation involves the dm_verity_loadpin_is_bdev_trusted function which is responsible for determining whether a block device is trusted based on its load pin configuration. When the device mapper subsystem processes a verity device that has not been properly initialized with a table structure, the function proceeds to access the table member without first verifying its existence through appropriate null checks. This flaw directly maps to CWE-476 which categorizes null pointer dereference vulnerabilities and aligns with common attack patterns documented in the ATT&CK framework under privilege escalation and system compromise techniques.
The operational impact of this vulnerability extends beyond simple system instability, as it can be leveraged by malicious actors to disrupt critical services or create persistent denial of service conditions. In production environments, this issue could affect systems that rely heavily on device mapper verity for data integrity verification, particularly those implementing full disk encryption with integrity checking or containerized applications utilizing verity-protected storage volumes. The vulnerability is especially concerning in server environments where continuous uptime is critical, as a single maliciously crafted device initialization could trigger the null pointer dereference and cause system-wide service interruption.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and null pointer checks within the affected kernel subsystem. System administrators should ensure that all Linux kernel updates are applied promptly to address this specific flaw, as the fix typically involves adding conditional checks before accessing table structures in the dm_verity_loadpin_is_bdev_trusted function. The recommended approach includes verifying that device table structures exist before attempting to dereference them and implementing appropriate error handling mechanisms to gracefully manage cases where expected configuration data is absent. Additionally, monitoring systems should be configured to detect unusual device initialization patterns that might indicate exploitation attempts, while maintaining regular kernel security updates to prevent similar vulnerabilities from arising in the future.