CVE-2026-23007: block: zero non-PI portion of auto integrity buffer

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-01-25 · updated 2026-10-21
Weakness: CWE-908

Description

In the Linux kernel, the following vulnerability has been resolved: block: zero non-PI portion of auto integrity buffer The auto-generated integrity buffer for writes needs to be fully initialized before being passed to the underlying block device, otherwise the uninitialized memory can be read back by userspace or anyone with physical access to the storage device. If protection information is generated, that portion of the integrity buffer is already initialized. The integrity data is also zeroed if PI generation is disabled via sysfs or the PI tuple size is 0. However, this misses the case where PI is generated and the PI tuple size is nonzero, but the metadata size is larger than the PI tuple. In this case, the remainder ("opaque") of the metadata is left uninitialized. Generalize the BLK_INTEGRITY_CSUM_NONE check to cover any case when the metadata is larger than just the PI tuple.

Affected products

Linux kernel: from 6.11.1 before 6.18.7; 6.11, 6.19-rc1, 6.19-rc2, 6.19-rc3, 6.19-rc4, 6.19-rc5 (+3) — fixed in 6.18.7

How to fix

Upgrade to a fixed version: Linux kernel 6.18.7. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-23007 or the next vulnerability affects your stack