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authorOleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>2017-02-27 14:30:25 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-10-08 10:14:19 +0200
commit9bcd5ceef96e71d57795c593e4dacf767f935c79 (patch)
tree671fea799ef7df60eb26b9a6d8edea769328968c /drivers/iommu
parentcadfa3a688d2f1f618677ddc66cb4f5cdbae6a81 (diff)
iommu/io-pgtable-arm: Check for leaf entry before dereferencing it
[ Upstream commit ed46e66cc1b3d684042f92dfa2ab15ee917b4cac ] 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_tyshchenko@epam.com> CC: Will Deacon <will.deacon@arm.com> CC: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/io-pgtable-arm.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index dad768caa9c5..18751b1dfd3d 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -335,8 +335,12 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)
pte |= ARM_LPAE_PTE_NSTABLE;
__arm_lpae_set_pte(ptep, pte, cfg);
- } else {
+ } else if (!iopte_leaf(pte, lvl)) {
cptep = iopte_deref(pte, data);
+ } else {
+ /* We require an unmap first */
+ WARN_ON(!selftest_running);
+ return -EEXIST;
}
/* Rinse, repeat */