CVE-2026-89574

In the Linux kernel, the following vulnerability has been resolved: dm array: validate array block headers on read array_block_check() validates blocknr and csum and nothing else, while node_check(), next to it, has bounded the structural fields since both were written. dm_array_cursor_next() takes its loop bound from the on-disk nr_entries and element_at() is unguarded pointer arithmetic, so a count larger than the block holds keeps the cursor in one block while the index grows past it and the read walks off the dm-bufio buffer -- dm_cache_load_mappings() drives it once per cache block at activation. Check the header against itself: reject a zero value_size, require max_entries to equal calc_max_entries() for that value_size and block size, and require nr_entries to fit. Equality rather than an upper bound, since a count below the real capacity trips BUG_ON() in fill_ablock() and trim_ablock(). Metadata dm-array writes satisfies all three.

CVSS v3 7.8 HIGH

7.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/2965787723084835b18dfe993cd450ebf5bd4540
https://git.kernel.org/stable/c/67adda7ed5da3e3b64f5b9021a02c21fb374fd9c
https://git.kernel.org/stable/c/9808ddffb4bc659352df3020cd84d9d864820ee5
https://git.kernel.org/stable/c/b33f76d33aaeacf3baf3370d8d64985169b36600

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-11 20:19

Updated : 2026-09-13 07:17

NVD link : CVE-2026-89574

Mitre link : CVE-2026-89574

CVE.ORG link : CVE-2026-89574

JSON object : View

Products Affected

No product.

CWE

No CWE.

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