Riskcovery

CVE-2025-38108

net_sched: red: fix a race in __red_change()

State
Published
Severity
7.8 High
Published
Jul 3, 2025
Updated
Oct 15, 2026
Reserved
Apr 16, 2025

Read the record on cve.org

Description

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

net_sched: red: fix a race in __red_change()

Gerrard Tai reported a race condition in RED, whenever SFQ perturb timer fires at the wrong time.

The race is as follows:

CPU 0 CPU 1 [1]: lock root [2]: qdisc_tree_flush_backlog() [3]: unlock root | | [5]: lock root | [6]: rehash | [7]: qdisc_tree_reduce_backlog() | [4]: qdisc_put()

This can be abused to underflow a parent's qlen.

Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog() should fix the race, because all packets will be purged from the qdisc before releasing the lock.

Scores

CVSSScoreVectorSource
3.17.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLinux

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • 0c8d13ac96070000da33f394f45e9c19638483c5 to before 2790c4ec481be45a80948d059cd7c9a06bc37493Affected
  • 0c8d13ac96070000da33f394f45e9c19638483c5 to before a1bf6a4e9264a685b0e642994031f9c5aad72414Affected
  • 0c8d13ac96070000da33f394f45e9c19638483c5 to before 110a47efcf23438ff8d31dbd9c854fae2a48bf98Affected
  • 0c8d13ac96070000da33f394f45e9c19638483c5 to before f569984417a4e12c67366e69bdcb752970de921dAffected
  • 0c8d13ac96070000da33f394f45e9c19638483c5 to before 2a71924ca4af59ffc00f0444732b6cd54b153d0eAffected
  • 0c8d13ac96070000da33f394f45e9c19638483c5 to before 4b755305b2b0618e857fdadb499365b5f2e478d1Affected
  • 0c8d13ac96070000da33f394f45e9c19638483c5 to before 444ad445df5496a785705019268a8a84b84484bbAffected
  • 0c8d13ac96070000da33f394f45e9c19638483c5 to before 85a3e0ede38450ea3053b8c45d28cf55208409b8Affected
LinuxLinux
  • 5.0Affected
  • before 5.0Not affected
  • 5.4.295 through 5.4.*Not affected
  • 5.10.239 through 5.10.*Not affected
  • 5.15.186 through 5.15.*Not affected
  • 6.1.142 through 6.1.*Not affected
  • 6.6.94 through 6.6.*Not affected
  • 6.12.34 through 6.12.*Not affected
  • 6.15.3 through 6.15.*Not affected
  • 6.16 and laterNot affected

References

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