powerpc/iommu: Fix the overflow validation in iommu_tce_check_ioba

Summary

In the Linux kernel, the following vulnerability has been resolved: powerpc/iommu: Fix the overflow validation in iommu_tce_check_ioba The commit b1af23d836f8 ("KVM: PPC: iommu: Unify TCE checking") unified IOBA parameter checking across KVM and VFIO into iommu_tce_check_ioba(). While doing so, the passed in argument npages is ignored and constant value '1' is used leaving out a possible overflow as the callers can legitimately be using npages > 1 for H_STUFF_TCE or H_PUT_TCE_INDIRECT cases. Fix this by accounting for 'npages', checking for arithmetic overflow, and verifying that the entire requested range (ioba - offset + npages) does not exceed the table capacity 'size'.

Timeline

1. Oct 6, 2026, 8:45 AM UTCCVE published
2. Oct 19, 2026, 9:16 AM UTCRecord last updated

Affected versions

• Linux Linux

  From b1af23d836f811137d504d14d4cbdd01929dec34 · fixed in 98d8dcc4ebd10523507d4478e148809a7771a213; From b1af23d836f811137d504d14d4cbdd01929dec34 · fixed in 9fd9c9bbb05417f468a11fb6d145d7ff61f4a868; From b1af23d836f811137d504d14d4cbdd01929dec34 · fixed in 3776bf56e06980e8a12c8c0565d9e6ac44965f03; From b1af23d836f811137d504d14d4cbdd01929dec34 · fixed in d6a1779129d936bc1fbab80181165da544eab736; From b1af23d836f811137d504d14d4cbdd01929dec34 · fixed in d48ceb6e1a6915c7bac4f902554a1047365cdff2; From b1af23d836f811137d504d14d4cbdd01929dec34 · fixed in 0543813753ef5cfbd6fa96694f7acf783fa01af7; From b1af23d836f811137d504d14d4cbdd01929dec34 · fixed in 314091243159f8e3749bc719bb129f423f72fd86; From b1af23d836f811137d504d14d4cbdd01929dec34 · fixed in 0b271f7d7f5ed45bc498a03ce0aa9cfd8402fc71

• Linux Linux

  4.12

• KernelLinux

  From 4.12.0 · fixed in 5.10.271; From 5.11.0 · fixed in 5.15.222; From 5.16.0 · fixed in 6.1.189; From 6.2.0 · fixed in 6.6.158; From 6.7.0 · fixed in 6.12.112; From 6.13.0 · fixed in 6.18.54; From 6.19.0 · fixed in 7.2.8

References 8