powerpc/iommu: Fix the overflow validation in iommu_tce_check_ioba

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The commit b1af23d836 ("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: b1af23d836 ("KVM: PPC: iommu: Unify TCE checking")
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Tested-by: R Nageswara Sastry <rnsastry@linux.ibm.com>
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Signed-off-by: Gautam Menghani <gautam@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>

...

This commit is contained in:

Shivaprasad G Bhat 2026-09-15 22:04:17 +05:30 • committed by Madhavan Srinivasan

parent 0a416ee20b

commit 0b271f7d7f

1 changed files with 1 additions and 1 deletions

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arch/powerpc/kernel/iommu.c

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