CVE-2026-98646 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, BPF developers, Linux system administrators, and security teams responsible for vulnerability management and system stability. These stakeholders should be aware of the vulnerability and the necessary steps to address it, including applying kernel updates and reviewing BPF iteration and listener socket handling to prevent similar issues.

Why it matters

A Linux kernel vulnerability was resolved, addressing a BPF context issue where cond_resched() was called from an invalid context in inet_csk_listen_stop(). This change ensures proper handling of listener sockets under BPF iteration, preventing potential system crashes or instability.

• Verify BPF iteration and listener socket handling to prevent similar issues
• Ensure kernel updates are applied to address BPF context handling
• Monitor for potential BPF-related issues in the Linux kernel

Technical summary

The Linux kernel vulnerability involves a BPF context issue where cond_resched() was called from an invalid context in inet_csk_listen_stop(). This was addressed by adding a check for the BPF context before calling cond_resched(), ensuring that the system handles listener sockets correctly under BPF iteration. The change prevents potential system crashes or instability by avoiding the call to cond_resched() when it is not allowed, thus maintaining the security and reliability of systems utilizing the Linux kernel. Developers should ensure kernel updates are applied and review BPF iteration and listener socket handling.

Defensive priority

Verify and apply kernel updates to ensure BPF context is properly handled

Recommended defensive actions

• Verify kernel version and apply updates if necessary
• Review BPF iteration and listener socket handling
• Monitor for similar BPF context issues
• Ensure proper synchronization in BPF context
• Verify affected product deployments exist in managed environments
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The issue arises from bpf_sock_destroy() running under rcu_read_lock() and encountering a listener socket with children in its accept queue, leading to a call to inet_csk_listen_stop() and subsequently cond_resched(). To address this, developers should verify BPF iteration and listener socket handling, ensure kernel updates are applied to address BPF context handling, and monitor for potential BPF-related issues in the Linux kernel. The resolution involves explicit checks for BPF context in critical sections, ensuring that operations如

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.