CVE-2025-38477

net/sched: sch_qfq: Fix race condition on qfq_aggregate

State: Published
Severity: 7.8 High
Published: Jul 28, 2025
Updated: Oct 15, 2026
Reserved: Apr 16, 2025

Description

In the Linux kernel, the following vulnerability has been resolved:

net/sched: sch_qfq: Fix race condition on qfq_aggregate

A race condition can occur when 'agg' is modified in qfq_change_agg (called during qfq_enqueue) while other threads access it concurrently. For example, qfq_dump_class may trigger a NULL dereference, and qfq_delete_class may cause a use-after-free.

This patch addresses the issue by:

1. Moved qfq_destroy_class into the critical section.

2. Added sch_tree_lock protection to qfq_dump_class and qfq_dump_class_stats.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	462dbc9101acd38e92eda93c0726857517a24bbd to before aa7a22c4d678bf649fd3a1d27debec583563414dAffected 462dbc9101acd38e92eda93c0726857517a24bbd to before d841aa5518508ab195b6781ad0d73ee378d713ddAffected 462dbc9101acd38e92eda93c0726857517a24bbd to before c6df794000147a3a02f79984aada4ce83f8d0a1eAffected 462dbc9101acd38e92eda93c0726857517a24bbd to before 466e10194ab81caa2ee6a332d33ba16bcceeeba6Affected 462dbc9101acd38e92eda93c0726857517a24bbd to before fbe48f06e64134dfeafa89ad23387f66ebca3527Affected 462dbc9101acd38e92eda93c0726857517a24bbd to before a6d735100f602c830c16d69fb6d780eebd8c9ae1Affected 462dbc9101acd38e92eda93c0726857517a24bbd to before c000a3a330d97f6c073ace5aa5faf94b9adb4b79Affected 462dbc9101acd38e92eda93c0726857517a24bbd to before 5e28d5a3f774f118896aec17a3a20a9c5c9dfc64Affected
LinuxLinux	3.8Affected before 3.8Not affected 5.4.297 through 5.4.Not affected 5.10.241 through 5.10.Not affected 5.15.190 through 5.15.Not affected 6.1.147 through 6.1.Not affected 6.6.100 through 6.6.Not affected 6.12.40 through 6.12.Not affected 6.15.8 through 6.15.*Not affected 6.16 and laterNot affected

Product

Versions

LinuxLinux

462dbc9101acd38e92eda93c0726857517a24bbd to before aa7a22c4d678bf649fd3a1d27debec583563414dAffected
462dbc9101acd38e92eda93c0726857517a24bbd to before d841aa5518508ab195b6781ad0d73ee378d713ddAffected
462dbc9101acd38e92eda93c0726857517a24bbd to before c6df794000147a3a02f79984aada4ce83f8d0a1eAffected
462dbc9101acd38e92eda93c0726857517a24bbd to before 466e10194ab81caa2ee6a332d33ba16bcceeeba6Affected
462dbc9101acd38e92eda93c0726857517a24bbd to before fbe48f06e64134dfeafa89ad23387f66ebca3527Affected
462dbc9101acd38e92eda93c0726857517a24bbd to before a6d735100f602c830c16d69fb6d780eebd8c9ae1Affected
462dbc9101acd38e92eda93c0726857517a24bbd to before c000a3a330d97f6c073ace5aa5faf94b9adb4b79Affected
462dbc9101acd38e92eda93c0726857517a24bbd to before 5e28d5a3f774f118896aec17a3a20a9c5c9dfc64Affected

LinuxLinux

3.8Affected
before 3.8Not affected
5.4.297 through 5.4.*Not affected
5.10.241 through 5.10.*Not affected
5.15.190 through 5.15.*Not affected
6.1.147 through 6.1.*Not affected
6.6.100 through 6.6.*Not affected
6.12.40 through 6.12.*Not affected
6.15.8 through 6.15.*Not affected
6.16 and laterNot affected

References

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