CVE Catalog

CVE-2026-93795

Low risk· EPSS 5%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.17%

5th percentile - higher than 5% of all known CVEs

Summary

In the Linux kernel blk-cgroup, the error path of blkg_create() has two issues: the online flag is set even when the blkg was not fully inserted, and blkg_put() is called instead of percpu_ref_kill(), leading to permanent memory leaks and preventing cgroup destruction.

Risk Assessment

Memory leaks and inability to destroy cgroups can lead to resource exhaustion and performance degradation.

Recommendation

Apply the Linux kernel patch that moves the online flag assignment to the success block and uses percpu_ref_kill() in the error path.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: fix leaks and online flag on radix_tree_insert failure When radix_tree_insert() fails in blkg_create(), the error path has two issues: 1. blkg->online is set to true unconditionally, even when the blkg was never fully inserted. Move the assignment inside the success block. 2. The error path calls blkg_put() without first calling percpu_ref_kill(). Because the refcount is still in percpu mode, percpu_ref_put() only does this_cpu_sub() without checking for zero, so blkg_release() is never triggered. This permanently leaks the blkg memory, its percpu iostat, policy data, the parent blkg reference, and the cgroup css reference — the latter preventing the cgroup from ever being destroyed. Fix by replacing blkg_put() with percpu_ref_kill(), matching the pattern used in blkg_destroy().

Vulnerability data from NVD (NIST) · CISA KEV · EPSS