CVE-2025-21679 btrfs: add the missing error handling inside get_canonical_dev_path

What is CVE-2025-21679?

CVE-2025-21679 is a medium-severity vulnerability in Linux kernel, published on 31 Jan 2025. 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:

btrfs: add the missing error handling inside get_canonical_dev_path

Inside function get_canonical_dev_path(), we call d_path() to get the final device path.

But d_path() can return error, and in that case the next strscpy() call will trigger an invalid memory access.

Add back the missing error handling for d_path().

Which versions are affected by CVE-2025-21679?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-21679?

Apply the vendor's patch.

Is CVE-2025-21679 being exploited?

There is no known exploitation of CVE-2025-21679 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 BELL-CVE-2025-21679, DEBIAN-CVE-2025-21679, GHSA-vh4g-mh2m-pgg3, UBUNTU-CVE-2025-21679.