nvdimm/btt: reject an arena whose nfree is below the lane count
Published Sep 16, 2026
7.8
HIGHCVSS 3.1
EPSS 0.18%
Description
The BTT info block's nfree field, the number of reserve free blocks, is read from the medium without validation. btt_freelist_init() and btt_rtt_init() size the per-lane freelist[] and rtt[] arrays by nfree, but the I/O path indexes them by the lane from nd_region_acquire_lane(), which is bounded by nd_region->num_lanes (ND_MAX_LANES), not by nfree. A crafted or foreign arena whose nfree is below the lane count makes freelist[lane]/rtt[lane] run past the allocation: an out-of-bounds write.
btt.rst documents the nlanes = min(nfree, num_cpus) invariant, which the code does not currently honor: num_lanes is ND_MAX_LANES regardless of nfree. Reject an arena whose nfree is below num_lanes at discovery, before the per-lane arrays are allocated, enforcing that invariant.
Affected products
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- Version StatusaffectedConstraints
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- Version 4.2StatusaffectedConstraints-
- Version 0StatusunaffectedConstraints<4.2
- Version 5.10.270StatusunaffectedConstraints<=5.10.*
- Version 5.15.221StatusunaffectedConstraints<=5.15.*
- Version 6.1.188StatusunaffectedConstraints<=6.1.*
- Version 6.12.110StatusunaffectedConstraints<=6.12.*
- Version 6.18.51StatusunaffectedConstraints<=6.18.*
- Version 6.6.157StatusunaffectedConstraints<=6.6.*
- Version 7.2.5StatusunaffectedConstraints<=7.2.*
- Version 7.3-rc1StatusunaffectedConstraints<=*
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
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| Linux | Linux | unaffected |
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| Linux | Linux | affected |
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No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
No CWE recorded.
References (9)
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-80565 Advisory
- https://git.kernel.org/stable/c/59d5cd1f42b4bab3609512c3cb3d3540d3d21da7
- https://git.kernel.org/stable/c/6a1f2e5ed9267ca19187038ac635393c165213ac
- https://git.kernel.org/stable/c/6b1faf1f099f7060b5f1f2f0d024132581f1726e
- https://git.kernel.org/stable/c/6f79d1a5f2611a3d36e9312be5425cd9cb397c51
- https://git.kernel.org/stable/c/9dfa11cef4750b67591307f2c62e47a23d60e4b7
- https://git.kernel.org/stable/c/eb491343d2d1784121ad9af91c25b338c28913c3
- https://git.kernel.org/stable/c/f6c5313aae794ecca8f762c1a3493de5c266f120
- https://git.kernel.org/stable/c/f9bf05c63b77d000e9c01f3e47af36973887d350
Change history (0)
No recorded changes yet.