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/
History

Mon, 17 Nov 2025 17:15:00 +0000

Type Values Removed Values Added
First Time appeared Debian
Debian debian Linux
Weaknesses CWE-415
CPEs cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.0:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.0:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.0:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.0:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.0:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.0:rc7:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.0:rc8:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:*
Vendors & Products Debian
Debian debian Linux
Metrics cvssV3_1

{'score': 6.3, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Mon, 03 Nov 2025 20:30:00 +0000

Type Values Removed Values Added
References

Mon, 03 Nov 2025 18:30:00 +0000

Type Values Removed Values Added
References

Mon, 14 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00061}

epss

{'score': 0.00051}


Wed, 04 Jun 2025 13:00:00 +0000


Fri, 23 May 2025 06:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-367
Metrics cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Important

cvssV3_1

{'score': 6.3, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H'}

threat_severity

Moderate


Wed, 21 May 2025 03:00:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Important


Tue, 20 May 2025 15:30:00 +0000

Type Values Removed Values Added
Description 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/
Title net_sched: qfq: Fix double list add in class with netem as child qdisc
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-05-20T15:21:44.793Z

Updated: 2025-11-03T19:57:15.106Z

Reserved: 2025-04-16T04:51:23.967Z

Link: CVE-2025-37913

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2025-05-20T16:15:27.837

Modified: 2025-11-17T17:11:37.813

Link: CVE-2025-37913

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-05-20T00:00:00Z

Links: CVE-2025-37913 - Bugzilla