cbcvebase.
CVE-2026-23067
published 2026-02-04

CVE-2026-23067: In the Linux kernel, the following vulnerability has been resolved: iommu/io-pgtable-arm: fix size_t signedness bug in unmap path __arm_lpae_unmap() returns…

PriorityP418medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.11%
1.4th percentile
In the Linux kernel, the following vulnerability has been resolved: iommu/io-pgtable-arm: fix size_t signedness bug in unmap path __arm_lpae_unmap() returns size_t but was returning -ENOENT (negative error code) when encountering an unmapped PTE. Since size_t is unsigned, -ENOENT (typically -2) becomes a huge positive value (0xFFFFFFFFFFFFFFFE on 64-bit systems). This corrupted value propagates through the call chain: __arm_lpae_unmap() returns -ENOENT as size_t -> arm_lpae_unmap_pages() returns it -> __iommu_unmap() adds it to iova address -> iommu_pgsize() triggers BUG_ON due to corrupted iova This can cause IOVA address overflow in __iommu_unmap() loop and trigger BUG_ON in iommu_pgsize() from invalid address alignment. Fix by returning 0 instead of -ENOENT. The WARN_ON already signals the error condition, and returning 0 (meaning "nothing unmapped") is the correct semantic for size_t return type. This matches the behavior of other io-pgtable implementations (io-pgtable-arm-v7s, io-pgtable-dart) which return 0 on error conditions.

Affected

13 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.18.8-1 (forky)linux 6.18.8-1 (forky)
linuxlinux
linuxlinux>= 3318f7b5cefbff96b1bb49584ac38d2c9997a830 < 41ec6988547819756fb65e94fc24f3e0dddf84ac41ec6988547819756fb65e94fc24f3e0dddf84ac
linuxlinux>= 3318f7b5cefbff96b1bb49584ac38d2c9997a830 < 374e7af67d9d9d6103c2cfc8eb32abfecf3a2fd8374e7af67d9d9d6103c2cfc8eb32abfecf3a2fd8
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.18.8-16.18.8-1
linuxlinux_kernel>= 6.16 < 6.18.86.18.8
ubuntulinux-azure-6.17
ubuntulinux-azure-fde-6.17
ubuntulinux-gcp-6.17
ubuntulinux-oem-6.17
ubuntulinux-oracle-6.17
ubuntulinux-realtime-6.17

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5LOW
vendor_redhat5.5MEDIUM
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