CVE-2021-47116 ext4: fix memory leak in ext4_mb_init_backend on error path.

What is CVE-2021-47116?

CVE-2021-47116 is a medium-severity denial of service vulnerability in Linux kernel, published on 15 Mar 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

ext4: fix memory leak in ext4_mb_init_backend on error path.

Fix a memory leak discovered by syzbot when a file system is corrupted with an illegally large s_log_groups_per_flex.

Weakness: CWE-401

Which versions are affected by CVE-2021-47116?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47116?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-47116 being exploited?

There is no known exploitation of CVE-2021-47116 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-47116, GHSA-q7g4-fr87-482c, UBUNTU-CVE-2021-47116.