CVE-2026-63831 Linux CVE debrief

Who should care

Linux kernel maintainers, mac802154 developers, and organizations using affected kernel versions should apply patches to prevent data corruption and potential security issues. This includes reviewing and updating affected kernel versions, monitoring for potential data corruption and security issues, and ensuring that patches are applied to prevent use-after-free issues and kernel crashes.

Technical summary

The mac802154 llsec implementation performs in-place cryptographic transformations on skb data without ensuring the data is not shared. This can lead to silent data corruption of other skb clones, use-after-free issues when the crypto API scatterwalk writes through a page that has already been freed by another clone's kfree_skb(), and kernel crashes under concurrent 802.15.4 traffic with security enabled. The fix involves calling skb_cow_data() before performing in-place crypto operations, ensuring the skb's data area is not shared. This change prevents data corruption and potential use-after-free issues.

Defensive priority

High priority for Linux kernel maintainers and developers to apply patches and ensure data integrity.

Recommended defensive actions

• Apply patches to call skb_cow_data() before performing in-place crypto operations
• Review and update affected kernel versions
• Monitor for potential data corruption and security issues
• Verify patch application and test for vulnerabilities
• Track exceptions and retest remediated assets
• Close the item only after evidence is documented
• Review compensating controls for exposed systems while remediation is scheduled and verified

Evidence notes

The vulnerability was found by 0sec using automated source analysis. The fix involves calling skb_cow_data() to ensure the skb's data area is not shared before performing in-place crypto operations. This change prevents data corruption and potential use-after-free issues. Linux kernel maintainers should review the patch and apply it to affected kernel versions. The patch ensures that the skb's data area is not shared, preventing silent data corruption of other skb clones, use-after-free issues, and kernel crashes under concurrent 802.15.4 traffic with security enabled.

Official resources