摘要:

In the Linux kernel, the following vulnerability has been resolved:btrfs: zoned: fix calc_available_free_space() for zoned modecalc_available_free_space() returns the total size of metadata (orsystem) block groups, which can be allocated from unallocated diskspace. The logic is wrong on zoned mode in two places.First, the calculation of data_chunk_size is wrong. We always allocateone zone as one chunk, and no partial allocation of a zone. So, weshould use zone_size (= data_sinfo->chunk_size) as it is.Second, the result avail may not be zone aligned. Since we alwaysallocate one zone as one chunk on zoned mode, returning non-zone sizealigned bytes will result in less pressure on the async metadata reclaimprocess.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 andend up in ENOSPC. We can align down to the zone size to avoid that.

安全等级: Low

公告ID: KylinSec-SA-2024-3442

发布日期: 2024年8月28日

关联CVE: CVE-2024-42231