CVE-2025-21703
Published: February 19, 2025Last modified: February 19, 2025
Description
In the Linux kernel, the following vulnerability has been resolved: netem: Update sch->q.qlen before qdisc_tree_reduce_backlog() qdisc_tree_reduce_backlog() notifies parent qdisc only if child qdisc becomes empty, therefore we need to reduce the backlog of the child qdisc before calling it. Otherwise it would miss the opportunity to call cops->qlen_notify(), in the case of DRR, it resulted in UAF since DRR uses ->qlen_notify() to maintain its active list.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.8 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Not affected (6.1.33-r0) |
| Stream | linux-lts | Not affected (6.1.33-r0) |
References
- https://git.kernel.org/stable/c/1f8e3f4a4b8b90ad274dfbc66fc7d55cb582f4d5
- https://git.kernel.org/stable/c/6312555249082d6d8cc5321ff725df05482d8b83
- https://git.kernel.org/stable/c/638ba5089324796c2ee49af10427459c2de35f71
- https://git.kernel.org/stable/c/7b79ca9a1de6a428d486ff52fb3d602321c08f55
- https://git.kernel.org/stable/c/7f31d74fcc556a9166b1bb20515542de7bb939d1
- https://git.kernel.org/stable/c/839ecc583fa00fab785fde1c85a326743657fd32
- https://git.kernel.org/stable/c/98a2c685293aae122f688cde11d9334dddc5d207
- https://git.kernel.org/stable/c/e395fec75ac2dbffc99b4bce57b7f1f3c5449f2c