[PATCH 3/5] iommu/vt-d: Add RMRR base and end addresses sanity check

Lu Baolu
2020-01-15T03:05:34Z

From: Barret Rhoden <brho@google.com>

The VT-d spec specifies requirements for the RMRR entries base and
end (called 'Limit' in the docs) addresses.

This commit will cause the DMAR processing to mark the firmware as
tainted if any RMRR entries that do not meet these requirements.

Signed-off-by: Barret Rhoden <brho@google.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/intel-iommu.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0505731b9e47..c6843642f462 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4454,13 +4454,24 @@ static void __init init_iommu_pm_ops(void)
static inline void init_iommu_pm_ops(void) {}
#endif /* CONFIG_PM */

+static int rmrr_sanity_check(struct acpi_dmar_reserved_memory *rmrr)
+{
+ if (!IS_ALIGNED(rmrr->base_address, PAGE_SIZE) ||
+ !IS_ALIGNED(rmrr->end_address + 1, PAGE_SIZE) ||
+ rmrr->end_address <= rmrr->base_address ||
+ arch_rmrr_sanity_check(rmrr))
+ return -EINVAL;
+
+ return 0;
+}
+
int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg)
{
struct acpi_dmar_reserved_memory *rmrr;
struct dmar_rmrr_unit *rmrru;

rmrr = (struct acpi_dmar_reserved_memory *)header;
- if (arch_rmrr_sanity_check(rmrr))
+ if (rmrr_sanity_check(rmrr))
WARN_TAINT(1, TAINT_FIRMWARE_WORKAROUND,
"Your BIOS is broken; bad RMRR [%#018Lx-%#018Lx]\n"
"BIOS vendor: %s; Ver: %s; Product Version: %s\n",