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/
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History
Wed, 04 Jun 2025 13:00:00 +0000
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Fri, 23 May 2025 06:45:00 +0000
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Weaknesses | CWE-367 | |
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cvssV3_1
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cvssV3_1
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Wed, 21 May 2025 03:00:00 +0000
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threat_severity
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cvssV3_1
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Tue, 20 May 2025 15:30:00 +0000
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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 |
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Status: PUBLISHED
Assigner: Linux
Published: 2025-05-20T15:21:44.793Z
Updated: 2025-06-04T12:57:26.662Z
Reserved: 2025-04-16T04:51:23.967Z
Link: CVE-2025-37913

No data.

Status : Awaiting Analysis
Published: 2025-05-20T16:15:27.837
Modified: 2025-06-04T13:15:26.490
Link: CVE-2025-37913
