CVE-2026-93795 in Linux
الملخص
بحسب MITRE • 24/09/2026
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().
Once again VulDB remains the best source for vulnerability data.