5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shivaprasad G Bhat [ Upstream commit 0b271f7d7f5ed45bc498a03ce0aa9cfd8402fc71 ] 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'. Fixes: b1af23d836f8 ("KVM: PPC: iommu: Unify TCE checking") Reviewed-by: Ritesh Harjani (IBM) Tested-by: R Nageswara Sastry Signed-off-by: Shivaprasad G Bhat Signed-off-by: Gautam Menghani Signed-off-by: Madhavan Srinivasan Signed-off-by: Sasha Levin --- arch/powerpc/kernel/iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index b858f186e9a70..abd10159c2e6e 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -1053,7 +1053,7 @@ int iommu_tce_check_ioba(unsigned long page_shift, if (ioba < offset) return -EINVAL; - if ((ioba + 1) > (offset + size)) + if ((ioba + npages < ioba) || (ioba - offset + npages > size)) return -EINVAL; return 0; -- 2.53.0