CVE-2026-74493 Linux CVE debrief

Who should care

Linux kernel users and administrators, as well as developers working with the net/smc module, should be aware of this vulnerability and take steps to mitigate it. Affected systems may be vulnerable to use-after-free attacks, which could lead to denial of service or code execution. System administrators should review system configurations and ensure proper termination of link groups. Developers should verify and apply patches to prevent potential use-after-free vulnerabilities. Security teams should monitor system logs for potential exploitation attempts and review compensating controls for exposed systems while remediation is scheduled and verified. Asset inventory and vulnerability management teams should track exceptions and retest remediated assets to ensure that the vulnerability is properly mitigated. Those responsible for change management and incident response should be aware of the potential impact of this vulnerability and plan accordingly. This includes tracking the status of patches and updates, as well as identifying potential workarounds or mitigations. In addition, those responsible for monitoring and detection should review relevant logs and implement additional monitoring to detect potential exploitation attempts. Those responsible for rollback and change windows should plan for the deployment of patches and updates, and ensure that proper testing and validation are performed before deployment. Finally, those responsible for source tracking and vulnerability management should ensure that affected systems are properly tracked and that the vulnerability is properly mitigated. This may involve working with vendors to obtain patches or updates, as well as implementing additional security controls to prevent exploitation. Overall, a coordinated effort is required to properly mitigate this vulnerability and prevent potential attacks. This includes communication and collaboration between different teams and stakeholders, as well as a thorough understanding of the vulnerability and its potential impact. By working together and taking a proactive approach, organizations can reduce the risk of exploitation and protect their systems and data. To further aid

Technical summary

The Linux kernel vulnerability allows for a use-after-free during link group termination in the net/smc module. The __smc_lgr_terminate() function drops conns_lock after finding a connection in lgr->conns_all, but before taking a reference on its socket. A concurrent close can unregister the connection and drop that reference, freeing the socket before the termination worker reaches sock_hold(). This vulnerability can be mitigated by verifying and applying Linux kernel patches.

Defensive priority

Linux kernel users should verify and apply patches to prevent potential use-after-free vulnerabilities.

Recommended defensive actions

• Verify and apply Linux kernel patches to prevent potential use-after-free vulnerabilities
• Review system configurations and ensure proper termination of link groups
• Monitor system logs for potential exploitation attempts
• Track exceptions and retest remediated assets
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• 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

Evidence notes

The Linux kernel vulnerability allows for a use-after-free during link group termination in the net/smc module. Evidence is based on official CVE and NVD records, as well as source references from the Linux kernel repository. Affected systems should verify and apply patches to prevent potential use-after-free vulnerabilities. The vulnerability has been publicly disclosed and may be targeted by attackers. Defenders should review system configurations and ensure proper termination of link groups.

Official resources