What’s Vulnerable › Vulnerabilities
CVE-2025-21745: blk-cgroup: Fix class @block_class's subsystem refcount leakage
- Severity: medium (CVSS 5.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2025-02-27 · updated 2026-10-15
Description
In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: Fix class @block_class's subsystem refcount leakage blkcg_fill_root_iostats() iterates over @block_class's devices by class_dev_iter_(init|next)(), but does not end iterating with class_dev_iter_exit(), so causes the class's subsystem refcount leakage. Fix by ending the iterating with class_dev_iter_exit().
Affected products
- Linux kernel: from 5.9 before 6.1.129; from 6.2 before 6.6.78; from 6.7 before 6.12.14; from 6.13 before 6.13.3 — fixed in 6.1.129, 6.12.14, 6.13.3, 6.6.78
How to fix
Upgrade to a fixed version: Linux kernel 6.1.129, 6.12.14, 6.13.3, 6.6.78. Check the vendor advisory for mitigations.
References
- https://git.kernel.org/stable/c/2ce09aabe009453d641a2ceb79e6461a2d4f3876
- https://git.kernel.org/stable/c/38287f779b34dfe959b4b681e909f2d3d52b88be
- https://git.kernel.org/stable/c/431b6ef2714be4d5babb802114987541a88b43b0
- https://git.kernel.org/stable/c/67c7f213e052b1aa6caba4a7e25e303bc6997126
- https://git.kernel.org/stable/c/993121481b5a87829f1e8163f47158b72679f309
- https://git.kernel.org/stable/c/d1248436cbef1f924c04255367ff4845ccd9025e
- https://git.kernel.org/stable/c/ffb494f1e7a047bd7a41b13796fcfb08fe5beafb
- https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html
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