{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98282", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.335Z", "datePublished": "2026-10-06T08:45:43.775Z", "dateUpdated": "2026-10-19T09:16:53.780Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:16:53.780Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/iommu: Fix the overflow validation in iommu_tce_check_ioba\n\nThe commit b1af23d836f8 (\"KVM: PPC: iommu: Unify TCE checking\") unified\nIOBA parameter checking across KVM and VFIO into iommu_tce_check_ioba().\nWhile doing so, the passed in argument npages is ignored and constant\nvalue '1' is used leaving out a possible overflow as the callers can\nlegitimately be using npages > 1 for H_STUFF_TCE or H_PUT_TCE_INDIRECT\ncases.\n\nFix this by accounting for 'npages', checking for arithmetic overflow,\nand verifying that the entire requested range (ioba - offset + npages)\ndoes not exceed the table capacity 'size'." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bad ioba/npages values come from a KVM guest's H_STUFF_TCE or H_PUT_TCE_INDIRECT hypercall registers. book3s_hv.c passes them to kvmppc_h_stuff_tce()/kvmppc_h_put_tce_indirect(), which call kvmppc_ioba_validate() -> iommu_tce_check_ioba(). The attacker is code running on the host in a guest, not a remote network peer.\nAC:L - The guest picks liobn, ioba (the last valid entry) and npages itself. The flawed check only tests ioba+1, so every such hypercall reliably walks kvmppc_tce_put() past stt->size. No race or outside condition is involved; only heap grooming affects how far exploitation goes.\nPR:L - The attacker needs kernel privilege inside their own guest, which any tenant of a pseries KVM VM has. Relative to the host, that is a low-privilege tenant position. The guest's TCE table already exists because QEMU creates it through KVM_CREATE_SPAPR_TCE_64 for the default PHB/VIO DMA windows.\nUI:N - The guest issues the hypercalls whenever it wants. No action by the host administrator or any other user is needed.\nS:C - A guest-controlled hypercall corrupts host kernel memory and touches the host's hardware IOMMU table outside the guest's DMA window. The impact therefore crosses the guest-to-host virtualization boundary.\nC:H - kvmppc_tce_put() and kvmppc_h_get_tce paths index stt->pages[] past the kmalloc'd flexible array, and the TCE iommu_unmap/map paths use entries beyond the window. This gives out-of-bounds access to host heap and IOMMU state that can be turned into host memory disclosure.\nI:H - In H_STUFF_TCE, npages is unbounded and tce_value is guest-chosen. kvmppc_tce_put() writes that 8-byte value through an out-of-bounds stt->pages[] pointer, or stores a newly allocated page pointer into the out-of-bounds slot. Both are host heap writes.\nA:H - Dereferencing an out-of-bounds stt->pages[] entry as a struct page, or corrupting the host heap and IOMMU tables, crashes or oopses the host. That takes down every VM running on it." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/powerpc/kernel/iommu.c" ], "versions": [ { "version": "b1af23d836f811137d504d14d4cbdd01929dec34", "lessThan": "98d8dcc4ebd10523507d4478e148809a7771a213", "status": "affected", "versionType": "git" }, { "version": "b1af23d836f811137d504d14d4cbdd01929dec34", "lessThan": "9fd9c9bbb05417f468a11fb6d145d7ff61f4a868", "status": "affected", "versionType": "git" }, { "version": "b1af23d836f811137d504d14d4cbdd01929dec34", "lessThan": "3776bf56e06980e8a12c8c0565d9e6ac44965f03", "status": "affected", "versionType": "git" }, { "version": "b1af23d836f811137d504d14d4cbdd01929dec34", "lessThan": "d6a1779129d936bc1fbab80181165da544eab736", "status": "affected", "versionType": "git" }, { "version": "b1af23d836f811137d504d14d4cbdd01929dec34", "lessThan": "d48ceb6e1a6915c7bac4f902554a1047365cdff2", "status": "affected", "versionType": "git" }, { "version": "b1af23d836f811137d504d14d4cbdd01929dec34", "lessThan": "0543813753ef5cfbd6fa96694f7acf783fa01af7", "status": "affected", "versionType": "git" }, { "version": "b1af23d836f811137d504d14d4cbdd01929dec34", "lessThan": "314091243159f8e3749bc719bb129f423f72fd86", "status": "affected", "versionType": "git" }, { "version": "b1af23d836f811137d504d14d4cbdd01929dec34", "lessThan": "0b271f7d7f5ed45bc498a03ce0aa9cfd8402fc71", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/powerpc/kernel/iommu.c" ], "versions": [ { "version": "4.12", "status": "affected" }, { "version": "0", "lessThan": "4.12", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.271", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.222", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.189", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.158", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.112", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.54", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.8", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "5.10.271" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "5.15.222" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.1.189" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.6.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.12.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.18.54" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "7.2.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/98d8dcc4ebd10523507d4478e148809a7771a213" }, { "url": "https://git.kernel.org/stable/c/9fd9c9bbb05417f468a11fb6d145d7ff61f4a868" }, { "url": "https://git.kernel.org/stable/c/3776bf56e06980e8a12c8c0565d9e6ac44965f03" }, { "url": "https://git.kernel.org/stable/c/d6a1779129d936bc1fbab80181165da544eab736" }, { "url": "https://git.kernel.org/stable/c/d48ceb6e1a6915c7bac4f902554a1047365cdff2" }, { "url": "https://git.kernel.org/stable/c/0543813753ef5cfbd6fa96694f7acf783fa01af7" }, { "url": "https://git.kernel.org/stable/c/314091243159f8e3749bc719bb129f423f72fd86" }, { "url": "https://git.kernel.org/stable/c/0b271f7d7f5ed45bc498a03ce0aa9cfd8402fc71" } ], "title": "powerpc/iommu: Fix the overflow validation in iommu_tce_check_ioba", "x_generator": { "engine": "bippy-1.2.0" } } } }