CVE-2026-89574 — dm array: validate array block headers on read
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 e…
Published: 2026-09-11 · CVSS: 7.8 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7