CVE Catalog

CVE-2025-37913

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.18%

8th percentile - higher than 8% of all known CVEs

Summary

In the Linux kernel, a double list addition of a class to the active list was found in the QFQ network scheduler when netem is used as a child qdisc. This causes memory corruption.

Risk Assessment

An attacker could exploit this vulnerability to cause a system crash or potentially escalate privileges by intentionally triggering reentrancy.

Recommendation

Apply the Linux kernel patch that checks whether the class is already active before adding it to the list.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: net_sched: qfq: Fix double list add in class with netem as child qdisc As described in Gerrard's report [1], there are use cases where a netem child qdisc will make the parent qdisc's enqueue callback reentrant. In the case of qfq, there won't be a UAF, but the code will add the same classifier to the list twice, which will cause memory corruption. This patch checks whether the class was already added to the agg->active list (cl_is_active) before doing the addition to cater for the reentrant case. [1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/

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