From: Oleksandr Tyshchenko <oleksandr_tyshche...@epam.com>
Do a check for already installed leaf entry at the current level before
dereferencing it in order to avoid walking the page table down with
wrong pointer to the next level.
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshche...@epam.com>
CC: Will Deacon <will.dea...@arm.com>
CC: Robin Murphy <robin.mur...@arm.com>
---
drivers/iommu/io-pgtable-arm-v7s.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c
b/drivers/iommu/io-pgtable-arm-v7s.c
index 1c049e2..8d6ca28 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -422,8 +422,12 @@ static int __arm_v7s_map(struct arm_v7s_io_pgtable *data,
unsigned long iova,
pte |= ARM_V7S_ATTR_NS_TABLE;
__arm_v7s_set_pte(ptep, pte, 1, cfg);
- } else {
+ } else if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) {
cptep = iopte_deref(pte, lvl);
+ } else {
+ /* We require an unmap first */
+ WARN_ON(!selftest_running);
+ return -EEXIST;
}
/* Rinse, repeat */
--
2.7.4
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