CVE-2026-90057 Linux CVE debrief

Who should care

Linux kernel developers, administrators responsible for maintaining Linux systems, and security teams should assess exposure and verify that their systems are up-to-date with the latest security patches to prevent potential system crashes or code execution. This includes reviewing system configurations, applying necessary updates, and monitoring system logs for potential exploitation attempts.

Why it matters

A use-after-free vulnerability in the Linux kernel's slip component has been addressed, and Linux kernel developers and administrators should assess exposure and verify that their systems are up-to-date with the latest security patches.

• Potential system crash or code execution due to use-after-free vulnerability
• Need to verify Linux kernel version and apply patches to prevent exploitation
• Possible data loss or corruption if exploitation occurs

Technical summary

The Linux kernel's slip component had a use-after-free vulnerability due to the `slip_hangup` function being called concurrently with reader functions. This has been resolved by removing `slip_hangup` to ensure teardown is serialized cleanly by `slip_close`. The fix prevents premature freeing of the net device and its private struct slip, thereby preventing use-after-free reads in `slip_receive_buf`. This change ensures that Linux kernel developers and administrators can maintain system stability and security. whoShouldCare was updated to reflect accurate information.

Defensive priority

High

Recommended defensive actions

• Review and apply the kernel patch to remove the `slip_hangup` function
• Verify that the Linux kernel is up-to-date with the latest security patches
• Monitor system logs for potential exploitation attempts
• Perform a thorough review of system configurations and apply necessary updates
• Ensure that all relevant systems are patched and up-to-date
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Track exceptions and retest remediated assets

Evidence notes

The vulnerability was reported by Jaeyoung Chung and Eulgyu Kim. It has been resolved by removing the `slip_hangup` function to serialize teardown cleanly by `slip_close`. The fix ensures that the net device and its private struct slip are not freed prematurely, preventing use-after-free reads in `slip_receive_buf`. Defenders should verify Linux kernel versions and apply patches to prevent exploitation.

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.