Description

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

net_sched: Flush gso_skb list too during ->change()

Previously, when reducing a qdisc's limit via the ->change() operation, only
the main skb queue was trimmed, potentially leaving packets in the gso_skb
list. This could result in NULL pointer dereference when we only check
sch->limit against sch->q.qlen.

This patch introduces a new helper, qdisc_dequeue_internal(), which ensures
both the gso_skb list and the main queue are properly flushed when trimming
excess packets. All relevant qdiscs (codel, fq, fq_codel, fq_pie, hhf, pie)
are updated to use this helper in their ->change() routines.

Classification

CVE ID: CVE-2025-37992

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.03% (probability of being exploited)

EPSS Percentile: 7.58% (scored less or equal to compared to others)

EPSS Date: 2025-06-19 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-37992
https://git.kernel.org/stable/c/d3336f746f196c6a53e0480923ae93939f047b6c
https://git.kernel.org/stable/c/d38939ebe0d992d581acb6885c1723fa83c1fb2c
https://git.kernel.org/stable/c/a7d6e0ac0a8861f6b1027488062251a8e28150fd
https://git.kernel.org/stable/c/d1365ca80b012d8a7863e45949e413fb61fa4861
https://git.kernel.org/stable/c/fe88c7e4fc2c1cd75a278a15ffbf1689efad4e76
https://git.kernel.org/stable/c/2d3cbfd6d54a2c39ce3244f33f85c595844bd7b8

Timeline