What’s Vulnerable › Vulnerabilities

CVE-2026-98017: net/sched: defer qdisc freeing after failed creation

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-25 · updated 2026-10-19

Description

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.

Affected products

• Linux kernel: 4.16 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/156a3bab69744e9225bb9eff8c5cc53da18d5a2e
• https://git.kernel.org/stable/c/20bf6fa34b345333971bd4464a322cce87b83f4e
• https://git.kernel.org/stable/c/5bfe927c5b4b290fad529186218c728589b4b101
• https://git.kernel.org/stable/c/6a1b49bb9fdf9e8e7aa38e8cd635c0cc4074447d
• https://git.kernel.org/stable/c/96a27a3e64e7c87abade03fb2ad04ed66992a89a
• https://git.kernel.org/stable/c/e6662f2100f8d33b0f4d0047c219efd6bba186ea

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