CVE-2026-93795 — blk-cgroup: fix leaks and online flag on radix_tree_insert failure
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().
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ 7fcf2b033b84e261dca283bc2911aaea4b07b525 and < 0f840db042caee9d2f3dcdcf97d6674f6e4c1e30≥ 7fcf2b033b84e261dca283bc2911aaea4b07b525 and < f53945d7c712efe63fadbcc5ffed6370871fd0d3≥ 7fcf2b033b84e261dca283bc2911aaea4b07b525 and < ada8270ccdb6f212da5eb22614c28ea418746a4a≥ 7fcf2b033b84e261dca283bc2911aaea4b07b525 and < c3650be82ef6e7af13b79b2d10a7363bdf54aa7f≥ 7fcf2b033b84e261dca283bc2911aaea4b07b525 and < 6e85f02d45b5977c0326a8d854c6db878aa6b34a≥ 7fcf2b033b84e261dca283bc2911aaea4b07b525 and < 4c0d150fb98ea40760611979f4e664c244b20966≥ 7fcf2b033b84e261dca283bc2911aaea4b07b525 and < dbbca20764382b4d411ec2918f4e278ffe547accversion 5.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 15, 2026 → Oct 16, 2026 · 2 reading(s) · max 0.17%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
7 on the record
- git.kernel.org/stable/c/6e85f02d45b5977c0326a8d854c6db878aa6b34a
- git.kernel.org/stable/c/dbbca20764382b4d411ec2918f4e278ffe547acc
- git.kernel.org/stable/c/0f840db042caee9d2f3dcdcf97d6674f6e4c1e30
- git.kernel.org/stable/c/c3650be82ef6e7af13b79b2d10a7363bdf54aa7f
- git.kernel.org/stable/c/ada8270ccdb6f212da5eb22614c28ea418746a4a
- git.kernel.org/stable/c/4c0d150fb98ea40760611979f4e664c244b20966
- git.kernel.org/stable/c/f53945d7c712efe63fadbcc5ffed6370871fd0d3
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 2d
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 2d
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 3d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 3d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 3d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 3d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-93795 is "blk-cgroup: fix leaks and online flag on radix_tree_insert failure", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.17% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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