CVE-2025-37890

In the Linux kernel, the following vulnerability has been resolved: net_sched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc As described in Gerrard's report [1], we have a UAF case when an hfsc class has a netem child qdisc. The crux of the issue is that hfsc is assuming that checking for cl->qdisc->q.qlen == 0 guarantees that it hasn't inserted the class in the vttree or eltree (which is not true for the netem duplicate case). This patch checks the n_active class variable to make sure that the code won't insert the class in the vttree or eltree twice, catering for the reentrant case. [1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/
CVSS

No CVSS.

Configurations

No configuration.

History

03 Nov 2025, 20:18

Type Values Removed Values Added
References
  • () https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html -

03 Nov 2025, 18:15

Type Values Removed Values Added
References
  • () https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html -

04 Jun 2025, 13:15

Type Values Removed Values Added
New CVE

Information

Published : 2025-05-16 13:15

Updated : 2025-11-03 20:18


NVD link : CVE-2025-37890

Mitre link : CVE-2025-37890

CVE.ORG link : CVE-2025-37890


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Products Affected

No product.

CWE

No CWE.