CVE-2026-99086

Published Oct 23, 2026

Description

In the Linux kernel, the following vulnerability has been resolved: dm-integrity: validate the superblock on resume dm_integrity_resume() re-reads the superblock from the device so that it picks up the flags and the recalculate position. It performs no validation on the result, while the constructor validates the superblock it reads and sizes all the in-memory structures according to it. The user may modify the superblock on the underlying device while the dm-integrity device is suspended, so that the two no longer agree. In particular, access_journal_data() shifts the journal entry index by ic->sb->log2_sectors_per_block, while ic->journal_section_sectors and the journal page list were computed with the value that was present at constructor time. Increasing log2_sectors_per_block makes the index run past the end of the journal, and dm-integrity then writes 512 bytes through lowmem_page_address(NULL). Snapshot the validated superblock in the constructor and refuse to resume if any of the fields that describe the on-disk geometry changed.

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References

Frequently Asked Questions

What is CVE-2026-99086? +
In the Linux kernel, the following vulnerability has been resolved: dm-integrity: validate the superblock on resume dm_integrity_resume() re-reads the superblock from the device so that it picks up the flags and the recalculate position. It performs no validation on the result, while the constructor validates the superblock it reads and sizes all the in-memory structures according to it. The user may modify the superblock on the underlying device while the dm-integrity device is suspended, so that the two no longer agree. In particular, access_journal_data() shifts the journal entry index by ic->sb->log2_sectors_per_block, while ic->journal_section_sectors and the journal page list were computed with the value that was present at constructor time. Increasing log2_sectors_per_block makes the index run past the end of the journal, and dm-integrity then writes 512 bytes through lowmem_page_address(NULL). Snapshot the validated superblock in the constructor and refuse to resume if any of the fields that describe the on-disk geometry changed.
How do I check if I'm vulnerable to CVE-2026-99086? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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