CVE-2021-46972
5.5 · MEDIUMOverview
CVE-2021-46972 is a medium-severity vulnerability affecting linux linux_kernel. It was published on February 27, 2024 and has a CVSS 3.1 base score of 5.5 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical Description
In the Linux kernel, the following vulnerability has been resolved:
ovl: fix leaked dentry
Since commit 6815f479ca90 ("ovl: use only uppermetacopy state in
ovl_lookup()"), overlayfs doesn't put temporary dentry when there is a
metacopy error, which leads to dentry leaks when shutting down the related
superblock:
overlayfs: refusing to follow metacopy origin for (/file0)
...
BUG: Dentry (____ptrval____){i=3f33,n=file3} still in use (1) [unmount of overlay overlay]
...
WARNING: CPU: 1 PID: 432 at umount_check.cold+0x107/0x14d
CPU: 1 PID: 432 Comm: unmount-overlay Not tainted 5.12.0-rc5 #1
...
RIP: 0010:umount_check.cold+0x107/0x14d
...
Call Trace:
d_walk+0x28c/0x950
? dentry_lru_isolate+0x2b0/0x2b0
? __kasan_slab_free+0x12/0x20
do_one_tree+0x33/0x60
shrink_dcache_for_umount+0x78/0x1d0
generic_shutdown_super+0x70/0x440
kill_anon_super+0x3e/0x70
deactivate_locked_super+0xc4/0x160
deactivate_super+0xfa/0x140
cleanup_mnt+0x22e/0x370
__
Remediation
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| linux | linux_kernel | >= 5.8, < 5.10.35 | Affected |
References
Frequently Asked Questions
What is CVE-2021-46972?
CVE-2021-46972 is a medium-severity vulnerability affecting linux linux_kernel. It was published on February 27, 2024 and has a CVSS 3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2021-46972?
This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2021-46972?
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-46972?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-46972 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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