Bug 2348654 (CVE-2025-21745)

Summary: CVE-2025-21745 kernel: blk-cgroup: Fix class @block_class's subsystem refcount leakage
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-02-27 03:06:35 UTC 
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().
Comment 1 Mauro Matteo Cascella 2025-02-27 17:39:26 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022600-CVE-2025-21745-19ee@gregkh/T