UBUNTU-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.
02 / AFFECTED SOFTWARE
Affected packages
9 explicit affected versions
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38 explicit affected versions
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7 explicit affected versions
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14 explicit affected versions
5 explicit affected versions
3 explicit affected versions
26 explicit affected versions
12 explicit affected versions
44 explicit affected versions
4 explicit affected versions
4 explicit affected versions
16 explicit affected versions
9 explicit affected versions
12 explicit affected versions
13 explicit affected versions
7 explicit affected versions
6 explicit affected versions
13 explicit affected versions
7 explicit affected versions
10 explicit affected versions
14 explicit affected versions
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3 explicit affected versions
16 explicit affected versions
43 explicit affected versions
14 explicit affected versions
5 explicit affected versions
7 explicit affected versions
11 explicit affected versions
35 explicit affected versions
12 explicit affected versions
13 explicit affected versions
6 explicit affected versions
12 explicit affected versions
50 explicit affected versions
14 explicit affected versions
12 explicit affected versions
27 explicit affected versions
12 explicit affected versions
7 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/64d2c847ba380e07b9072d65a50aa6469d2aa43f
- https://git.kernel.org/stable/c/64d2c847ba380e07b9072d65a50aa6469d2aa43f
- https://git.kernel.org/stable/c/8548903b1999bba02a2b894ad750ab8eb1f40307
- https://ubuntu.com/security/CVE-2024-42231
- https://ubuntu.com/security/notices/USN-7089-1
- https://ubuntu.com/security/notices/USN-7089-2
- https://ubuntu.com/security/notices/USN-7089-3
- https://ubuntu.com/security/notices/USN-7089-4
- https://ubuntu.com/security/notices/USN-7089-5
- https://ubuntu.com/security/notices/USN-7089-6
- https://ubuntu.com/security/notices/USN-7089-7
- https://ubuntu.com/security/notices/USN-7090-1
- https://ubuntu.com/security/notices/USN-7095-1
- https://ubuntu.com/security/notices/USN-7156-1
- https://www.cve.org/CVERecord?id=CVE-2024-42231