{"id":"CVE-2026-23067","state":"PUBLISHED","title":"iommu/io-pgtable-arm: fix size_t signedness bug in unmap path","description":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/io-pgtable-arm: fix size_t signedness bug in unmap path\n\n__arm_lpae_unmap() returns size_t but was returning -ENOENT (negative\nerror code) when encountering an unmapped PTE. Since size_t is unsigned,\n-ENOENT (typically -2) becomes a huge positive value (0xFFFFFFFFFFFFFFFE\non 64-bit systems).\n\nThis corrupted value propagates through the call chain:\n  __arm_lpae_unmap() returns -ENOENT as size_t\n  -> arm_lpae_unmap_pages() returns it\n  -> __iommu_unmap() adds it to iova address\n  -> iommu_pgsize() triggers BUG_ON due to corrupted iova\n\nThis can cause IOVA address overflow in __iommu_unmap() loop and\ntrigger BUG_ON in iommu_pgsize() from invalid address alignment.\n\nFix by returning 0 instead of -ENOENT. The WARN_ON already signals\nthe error condition, and returning 0 (meaning \"nothing unmapped\")\nis the correct semantic for size_t return type. This matches the\nbehavior of other io-pgtable implementations (io-pgtable-arm-v7s,\nio-pgtable-dart) which return 0 on error conditions.","publishedAt":"2026-02-04T16:07:48.457Z","updatedAt":"2026-05-11T21:59:21.632Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3318f7b5cefbff96b1bb49584ac38d2c9997a830","status":"affected","lessThan":"41ec6988547819756fb65e94fc24f3e0dddf84ac","versionType":"git"},{"version":"3318f7b5cefbff96b1bb49584ac38d2c9997a830","status":"affected","lessThan":"374e7af67d9d9d6103c2cfc8eb32abfecf3a2fd8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/io-pgtable-arm.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.8","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/io-pgtable-arm.c"]}],"references":["https://git.kernel.org/stable/c/41ec6988547819756fb65e94fc24f3e0dddf84ac","https://git.kernel.org/stable/c/374e7af67d9d9d6103c2cfc8eb32abfecf3a2fd8"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/23xxx/CVE-2026-23067.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23067","state":"PUBLISHED","datePublished":"2026-02-04T16:07:48.457Z","dateUpdated":"2026-05-11T21:59:21.632Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-01-13T15:37:45.954Z"},"containers":{"cna":{"title":"iommu/io-pgtable-arm: fix size_t signedness bug in unmap path","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/io-pgtable-arm: fix size_t signedness bug in unmap path\n\n__arm_lpae_unmap() returns size_t but was returning -ENOENT (negative\nerror code) when encountering an unmapped PTE. Since size_t is unsigned,\n-ENOENT (typically -2) becomes a huge positive value (0xFFFFFFFFFFFFFFFE\non 64-bit systems).\n\nThis corrupted value propagates through the call chain:\n  __arm_lpae_unmap() returns -ENOENT as size_t\n  -> arm_lpae_unmap_pages() returns it\n  -> __iommu_unmap() adds it to iova address\n  -> iommu_pgsize() triggers BUG_ON due to corrupted iova\n\nThis can cause IOVA address overflow in __iommu_unmap() loop and\ntrigger BUG_ON in iommu_pgsize() from invalid address alignment.\n\nFix by returning 0 instead of -ENOENT. The WARN_ON already signals\nthe error condition, and returning 0 (meaning \"nothing unmapped\")\nis the correct semantic for size_t return type. This matches the\nbehavior of other io-pgtable implementations (io-pgtable-arm-v7s,\nio-pgtable-dart) which return 0 on error conditions."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3318f7b5cefbff96b1bb49584ac38d2c9997a830","status":"affected","lessThan":"41ec6988547819756fb65e94fc24f3e0dddf84ac","versionType":"git"},{"version":"3318f7b5cefbff96b1bb49584ac38d2c9997a830","status":"affected","lessThan":"374e7af67d9d9d6103c2cfc8eb32abfecf3a2fd8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/io-pgtable-arm.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.8","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/io-pgtable-arm.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/41ec6988547819756fb65e94fc24f3e0dddf84ac"},{"url":"https://git.kernel.org/stable/c/374e7af67d9d9d6103c2cfc8eb32abfecf3a2fd8"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T21:59:21.632Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.18.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.19"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}