Vulnerability Details CVE-2025-38620
In the Linux kernel, the following vulnerability has been resolved:
zloop: fix KASAN use-after-free of tag set
When a zoned loop device, or zloop device, is removed, KASAN enabled
kernel reports "BUG KASAN use-after-free" in blk_mq_free_tag_set(). The
BUG happens because zloop_ctl_remove() calls put_disk(), which invokes
zloop_free_disk(). The zloop_free_disk() frees the memory allocated for
the zlo pointer. However, after the memory is freed, zloop_ctl_remove()
calls blk_mq_free_tag_set(&zlo->tag_set), which accesses the freed zlo.
Hence the KASAN use-after-free.
zloop_ctl_remove()
put_disk(zlo->disk)
put_device()
kobject_put()
...
zloop_free_disk()
kvfree(zlo)
blk_mq_free_tag_set(&zlo->tag_set)
To avoid the BUG, move the call to blk_mq_free_tag_set(&zlo->tag_set)
from zloop_ctl_remove() into zloop_free_disk(). This ensures that
the tag_set is freed before the call to kvfree(zlo).
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 6.7%
CVSS Severity
CVSS v3 Score 7.8
References
Products affected by CVE-2025-38620
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cpe:2.3:o:linux:linux_kernel:6.16