Tracker / CVE-2025-37890
CVE-2025-37890
High 7.8
In the Linux kernel, the following vulnerability has been resolved: net_sched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc As described in Gerrard's report [1], we have a UAF case when an hfsc class has a netem child qdisc. The crux of the issue is that hfsc is assuming that checking for cl->qdisc->q.qlen == 0 guarantees that it hasn't inserted the class in the vttree or eltree (which is not true for the netem duplicate case). This patch checks the n_active class variable to make sure that the code won't insert the class in the vttree or eltree twice, catering for the reentrant case. [1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/
Affected products and versions
| debian | debian_linux |
|---|---|
| linux | linux_kernel |
| linux | linux_kernel · 5.0.1 → 5.4.294 |
| linux | linux_kernel · 5.11 → 5.15.182 |
| linux | linux_kernel · 5.16 → 6.1.138 |
| linux | linux_kernel · 5.5 → 5.10.238 |
| linux | linux_kernel · 6.13 → 6.14.6 |
| linux | linux_kernel · 6.2 → 6.6.90 |
| linux | linux_kernel · 6.7 → 6.12.28 |
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.