CVE-2023-4389 Kernel: btrfs: double free in btrfs_get_root_ref()

What is CVE-2023-4389?

CVE-2023-4389 is a high-severity use after free vulnerability in Linux kernel, published on 16 Aug 2023. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A flaw was found in btrfs_get_root_ref in fs/btrfs/disk-io.c in the btrfs filesystem in the Linux Kernel due to a double decrement of the reference count. This issue may allow a local attacker with user privilege to crash the system or may lead to leaked internal kernel information.

Weakness: CWE-415

Which versions are affected by CVE-2023-4389?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2023-4389?

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-2023-4389 being exploited?

There is no known exploitation of CVE-2023-4389 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 AZL-27959, DEBIAN-CVE-2023-4389, GHSA-4g3m-89jh-2mrf, UBUNTU-CVE-2023-4389.