Tracker / CVE-2025-21971
CVE-2025-21971
High 7.8
In the Linux kernel, the following vulnerability has been resolved: net_sched: Prevent creation of classes with TC_H_ROOT The function qdisc_tree_reduce_backlog() uses TC_H_ROOT as a termination condition when traversing up the qdisc tree to update parent backlog counters. However, if a class is created with classid TC_H_ROOT, the traversal terminates prematurely at this class instead of reaching the actual root qdisc, causing parent statistics to be incorrectly maintained. In case of DRR, this could lead to a crash as reported by Mingi Cho. Prevent the creation of any Qdisc class with classid TC_H_ROOT (0xFFFFFFFF) across all qdisc types, as suggested by Jamal.
Affected products and versions
| linux | linux_kernel |
|---|---|
| linux | linux_kernel · 2.6.26 → 5.4.292 |
| linux | linux_kernel · 5.11 → 5.15.180 |
| linux | linux_kernel · 5.16 → 6.1.132 |
| linux | linux_kernel · 5.5 → 5.10.236 |
| linux | linux_kernel · 6.13 → 6.13.8 |
| linux | linux_kernel · 6.2 → 6.6.84 |
| linux | linux_kernel · 6.7 → 6.12.20 |
Analysis
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