Loading vulnerability…
CVE-2021-47579 affects the Linux kernel OverlayFS work-directory creation path. When OverlayFS invokes ovl_create_real() during ovl_workdir_create(), a cgroup2 filesystem can report mkdir success without instantiating the resulting dentry inode. This causes the WARN_ON check for a missing inode to fire. The upstream fix invokes ovl_mkdir_real() directly from ovl_workdir_create() and rejects this unsupported filesystem behavior earlier during OverlayFS setup.
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
What an attacker gets, and what they’ve been doing with it.
If you can’t patch tonight, do this now.
Patch, then assume compromise.
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
4 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A Linux kernel OverlayFS (ovl) issue involving a warning in ovl_create_real(). The content states that it has been resolved and addressed for Red Hat Enterprise Linux 8.
A Linux kernel OverlayFS flaw involving an uninstantiated dentry returned by cgroup2 mkdir operations. It can trigger a warning and has availability impact; Red Hat classifies it as Low severity (CVSS 4.1), while NVD scores it 5.5.
A Linux kernel OverlayFS issue in which use with the cgroup2 filesystem can cause ovl_create_real() to encounter an uninstantiated dentry and trigger a warning. The fix calls ovl_mkdir_real() directly from ovl_workdir_create() to reject the condition earlier.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.