CVE-2021-47579

CVE-2021-47579 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: ovl: fix warning in ovl_create_real() Syzbot triggered the following warning in ovl_workdir_create() -> ovl_create_real(): if (!err && WARN_ON(!newdentry->d_inode)) { The reason is that the cgroup2 filesystem returns from mkdir without instantiating the new dentry. Weird filesystems such as this will be rejected by overlayfs at a later stage during setup, but to prevent such a warning, call ovl_mkdir_real() directly from ovl_workdir_create() and reject this case early.

Frequently asked questions

What is CVE-2021-47579?
In the Linux kernel, the following vulnerability has been resolved: ovl: fix warning in ovl_create_real() Syzbot triggered the following warning in ovl_workdir_create() -> ovl_create_real(): if (!err && WARN_ON(!newdentry->d_inode)) { The reason is that the cgroup2 filesystem returns from mkdir without instantiating the new dentry. Weird filesystems such as this will be rejected by overlayfs at a later stage during setup, but to prevent such a warning, call ovl_mkdir_real() directly from ovl_workdir_create() and reject this case early.
How severe is CVE-2021-47579?
CVE-2021-47579 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-47579 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-47579?
CVE-2021-47579 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-47579?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2021-47579 have an EU (EUVD) identifier?
Yes. CVE-2021-47579 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34581.
When was CVE-2021-47579 published?
CVE-2021-47579 was published on 2024-06-19 and last updated on 2026-06-17.

References

Affected products (1)

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