From: Oleksandr Tyshchenko <[email protected]> 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 <[email protected]> CC: Will Deacon <[email protected]> CC: Robin Murphy <[email protected]> --- drivers/iommu/io-pgtable-arm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index feacc54..f9bc6eb 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 */ -- 2.7.4 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
