CVE-2021-47088 mm/damon/dbgfs: protect targets destructions with kdamond_lock

What is CVE-2021-47088?

CVE-2021-47088 is a high-severity use after free vulnerability in Linux kernel, published on 4 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:

mm/damon/dbgfs: protect targets destructions with kdamond_lock

DAMON debugfs interface iterates current monitoring targets in 'dbgfs_target_ids_read()' while holding the corresponding 'kdamond_lock'. However, it also destructs the monitoring targets in 'dbgfs_before_terminate()' without holding the lock. This can result in a use_after_free bug. This commit avoids the race by protecting the destruction with the corresponding 'kdamond_lock'.

Weakness: CWE-416

Which versions are affected by CVE-2021-47088?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47088?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2021-47088 being exploited?

There is no known exploitation of CVE-2021-47088 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-2021-47088, GHSA-3f3q-cv7c-w6c7, UBUNTU-CVE-2021-47088.