Commit 08090744 authored Feb 28, 2020 by Robin Murphy Committed by Joerg Roedel Mar 02, 2020

iommu/io-pgtable-arm: Fix IOVA validation for 32-bit



Since we ony support the TTB1 quirk for AArch64 contexts, and
consequently only for 64-bit builds, the sign-extension aspect of the
"are all bits above IAS consistent?" check should implicitly only apply
to 64-bit IOVAs. Change the type of the cast to ensure that 32-bit longs
don't inadvertently get sign-extended, and thus considered invalid, if
they happen to be above 2GB in the TTB0 region.

Reported-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Acked-by: Will Deacon <will@kernel.org>
Fixes: db690301 ("iommu/io-pgtable-arm: Prepare for TTBR1 usage")
Signed-off-by: Joerg Roedel <jroedel@suse.de>

parent 77a1bce8

drivers/iommu/io-pgtable-arm.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -468,7 +468,7 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova,
		arm_lpae_iopte *ptep = data->pgd;
		int ret, lvl = data->start_level;
		arm_lpae_iopte prot;
		long iaext = (long)iova >> cfg->ias;
		long iaext = (s64)iova >> cfg->ias;

		/* If no access, then nothing to do */
		if (!(iommu_prot & (IOMMU_READ \| IOMMU_WRITE)))
		@@ -645,7 +645,7 @@ static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
		struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
		struct io_pgtable_cfg *cfg = &data->iop.cfg;
		arm_lpae_iopte *ptep = data->pgd;
		long iaext = (long)iova >> cfg->ias;
		long iaext = (s64)iova >> cfg->ias;

		if (WARN_ON(!size \|\| (size & cfg->pgsize_bitmap) != size))
		return 0;

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