CVE-2025-21971
Last modified
CVE-2025-21971 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. 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.. EPSS estimates a 0.19% chance of exploitation in the next 30 days.
Description
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.
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions | Update |
|---|---|---|---|
| Linux | Linux Kernel | >= 2.6.26, < 5.4.292 | — |
| Linux | Linux Kernel | >= 5.5, < 5.10.236 | — |
| Linux | Linux Kernel | >= 5.11, < 5.15.180 | — |
| Linux | Linux Kernel | >= 5.16, < 6.1.132 | — |
| Linux | Linux Kernel | >= 6.2, < 6.6.84 | — |
| Linux | Linux Kernel | >= 6.7, < 6.12.20 | — |
| Linux | Linux Kernel | >= 6.13, < 6.13.8 | — |
| Linux | Linux Kernel | 2.6.25 | — |
| Linux | Linux Kernel | 6.14 | Rc1 |
References
Timeline
- Published
- Last Modified
- Status
- Modified
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