IT

Tracker / CVE-2025-38000

CVE-2025-38000

High 7.8

In the Linux kernel, the following vulnerability has been resolved: sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue() When enqueuing the first packet to an HFSC class, hfsc_enqueue() calls the child qdisc's peek() operation before incrementing sch->q.qlen and sch->qstats.backlog. If the child qdisc uses qdisc_peek_dequeued(), this may trigger an immediate dequeue and potential packet drop. In such cases, qdisc_tree_reduce_backlog() is called, but the HFSC qdisc's qlen and backlog have not yet been updated, leading to inconsistent queue accounting. This can leave an empty HFSC class in the active list, causing further consequences like use-after-free. This patch fixes the bug by moving the increment of sch->q.qlen and sch->qstats.backlog before the call to the child qdisc's peek() operation. This ensures that queue length and backlog are always accurate when packet drops or dequeues are triggered during the peek.

Affected products and versions

debian debian_linux
linux linux_kernel
linux linux_kernel · 4.8 → 5.4.294
linux linux_kernel · 5.11 → 5.15.185
linux linux_kernel · 5.16 → 6.1.141
linux linux_kernel · 5.5 → 5.10.238
linux linux_kernel · 6.13 → 6.14.9
linux linux_kernel · 6.2 → 6.6.93
linux linux_kernel · 6.7 → 6.12.31

Analysis

This page is not indexable yet.Until it carries original analysis — what it actually exposes, how to check in two minutes whether a system was touched, what to do if it was — the page stays noindex. The database decides that, not the template.

References