CVE Catalog

CVE-2026-98017

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Summary

In the Linux kernel, an RTM_NEWQDISC request could make clsact bind a populated shared ingress block during ->init(), publishing an embedded mini_Qdisc to lockless readers. If the same request had an invalid TCA_RATE, estimator setup failed after ->init(), and the unwind synchronously freed the containing qdisc while tc_run() might still hold it, leading to a use-after-free.

Risk Assessment

A use-after-free in the qdisc subsystem can lead to kernel crashes or potential code execution, especially since it only requires qdisc configuration privileges (CAP_NET_ADMIN).

Recommendation

Update the Linux kernel to a version containing the fix that retires failed qdiscs through the RCU helper instead of synchronous freeing.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: net/sched: defer qdisc freeing after failed creation An RTM_NEWQDISC request can make clsact bind a populated shared ingress block during ->init(), publishing an embedded mini_Qdisc to lockless readers. If the same request has an invalid TCA_RATE, estimator setup fails after ->init(); the unwind removes the pointer but synchronously frees its containing qdisc while tc_run() may still hold it. Retire failed qdiscs through the same RCU helper as normal destruction. Inline the synchronous free into the callback now that no direct callers remain.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS