CVE-2024-42231: In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: fix calc_available_free_space() for zoned mode calc_available_free...

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: fix calc_available_free_space() for zoned mode calc_available_free_space() returns the total size of metadata (or system) block groups, which can be allocated from unallocated disk space. The logic is wrong on zoned mode in two places. First, the calculation of data_chunk_size is wrong. We always allocate one zone as one chunk, and no partial allocation of a zone. So, we should use zone_size (= data_sinfo->chunk_size) as it is. Second, the result "avail" may not be zone aligned. Since we always allocate one zone as one chunk on zoned mode, returning non-zone size aligned bytes will result in less pressure on the async metadata reclaim process. This is serious for the nearly full state with a large zone size device. Allowing over-commit too much will result in less async reclaim work and end up in ENOSPC. We can align down to the zone size to avoid that.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.18%

8.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-682

Affected Software

Vendor	Product	Versions	Update
Linux	Linux Kernel	>= 6.7, < 6.9.9	—
Linux	Linux Kernel	6.10	Rc1

References

Timeline

Published: Jul 30, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2024-42231?

In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: fix calc_available_free_space() for zoned mode calc_available_free_space() returns the total size of metadata (or system) block groups, which can be allocated from unallocated disk space. The logic is wrong on zoned mode in two places. First, the calculation of data_chunk_size is wrong. We always allocate one zone as one chunk, and no partial allocation of a zone. So, we should use zone_size (= data_sinfo->chunk_size) as it is. Second, the result "avail" may not be zone aligned. Since we always allocate one zone as one chunk on zoned mode, returning non-zone size aligned bytes will result in less pressure on the async metadata reclaim process. This is serious for the nearly full state with a large zone size device. Allowing over-commit too much will result in less async reclaim work and end up in ENOSPC. We can align down to the zone size to avoid that.

How severe is CVE-2024-42231?

CVE-2024-42231 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.18% probability of exploitation in the next 30 days.

How do I fix CVE-2024-42231?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.