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/
Metrics
Affected Vendors & Products
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4271-1 | linux-6.1 security update |
Debian DLA |
DLA-4327-1 | linux security update |
Debian DSA |
DSA-5925-1 | linux security update |
EUVD |
EUVD-2025-15944 | 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/ |
Ubuntu USN |
USN-7649-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7649-2 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-7650-1 | Linux kernel (OEM) vulnerabilities |
Ubuntu USN |
USN-7654-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7654-2 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-7654-3 | Linux kernel (FIPS) vulnerabilities |
Ubuntu USN |
USN-7654-4 | Linux kernel (KVM) vulnerabilities |
Ubuntu USN |
USN-7654-5 | Linux kernel (Xilinx ZynqMP) vulnerabilities |
Ubuntu USN |
USN-7655-1 | Linux kernel (Intel IoTG) vulnerabilities |
Ubuntu USN |
USN-7665-1 | Linux kernel (Oracle) vulnerabilities |
Ubuntu USN |
USN-7665-2 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-7686-1 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-7711-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-7712-1 | Linux kernel (Azure FIPS) vulnerabilities |
Ubuntu USN |
USN-7712-2 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-7721-1 | Linux kernel (Azure) vulnerabilities |
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Mon, 03 Nov 2025 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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Mon, 03 Nov 2025 18:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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Mon, 14 Jul 2025 13:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
epss
|
epss
|
Wed, 04 Jun 2025 13:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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Fri, 23 May 2025 06:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-367 | |
| Metrics |
cvssV3_1
|
cvssV3_1
|
Wed, 21 May 2025 03:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
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 |
|
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-11-03T19:57:15.106Z
Reserved: 2025-04-16T04:51:23.967Z
Link: CVE-2025-37913
No data.
Status : Awaiting Analysis
Published: 2025-05-20T16:15:27.837
Modified: 2025-11-03T20:18:41.210
Link: CVE-2025-37913
OpenCVE Enrichment
Updated: 2025-06-27T09:26:51Z
Debian DLA
Debian DSA
EUVD
Ubuntu USN