CVE-2026-72107 Linux CVE debrief

Who should care

Linux kernel developers and users who rely on the dm era module should be aware of this vulnerability. They should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance. Additionally, they should plan vendor-supported updates or mitigations through normal change control where exposure is confirmed. Compensating controls for exposed systems should be reviewed while remediation is scheduled and verified. Relevant monitoring, detection, and logs for exposed assets should be checked for extra review. Exceptions, retesting of remediated assets, and closing the item only after evidence is documented are also important. System administrators and security teams responsible for Linux kernel deployments should prioritize patching or mitigating this vulnerability to prevent potential vmalloc-out-of-bounds access errors. Vulnerability management and security teams should track this issue and ensure that appropriate measures are taken to protect against exploitation. Operators of systems using the dm era module should also be aware of the potential impact and take steps to verify their deployments and apply necessary patches or mitigations. This includes reviewing system logs for potential vmalloc-out-of-bounds access errors and taking corrective action if necessary. Overall, anyone responsible for the security and maintenance of Linux kernel deployments that utilize the dm era module should be aware of this vulnerability and take proactive steps to address it. This may involve coordinating with vendors, applying patches, and monitoring system logs for signs of exploitation. By taking these steps, organizations can help prevent potential security breaches and ensure the integrity of their Linux kernel deployments. The vulnerability highlights the importance of keeping the Linux kernel up-to-date and applying security patches in a timely manner. It also underscores the need for robust vulnerability management practices, including regular security audits and monitoring of system logs. By prioritizing security and taking proactive steps to address this vulnerability, organizations can help protect their Linux kernel-based

Technical summary

The Linux kernel's dm era module has a vulnerability that allows for out-of-bounds memory access when the start sector is non-zero. This can lead to a vmalloc-out-of-bounds access error as reported by KASAN. The issue is caused by the era_map() function calculating the writeset block before applying the target offset. To fix this, apply the target offset before calculating the era block. This change ensures that the module correctly handles tables with non-zero start sectors and prevents out-of-bounds memory access. The fix involves modifying the era_map() function to apply the target offset before calculating the writeset block.

Defensive priority

High

Recommended defensive actions

• Apply the target offset before calculating the era block to prevent out-of-bounds memory access
• Update the Linux kernel to the latest version
• Monitor system logs for potential vmalloc-out-of-bounds access errors
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability is caused by the era_map() function calculating the writeset block before applying the target offset, leading to out-of-bounds memory access. The issue is resolved by applying the target offset before calculating the era block. Evidence of this issue is limited, but it has been reported by KASAN as a vmalloc-out-of-bounds access error. Further verification is needed to confirm affected deployments and assess potential impact.

Official resources