Commit 11f1a776 authored Mar 25, 2014 by Joerg Roedel

iommu/vt-d: Check for NULL pointer in dmar_acpi_dev_scope_init()



When ir_dev_scope_init() is called via a rootfs initcall it
will check for irq_remapping_enabled before it calls
(indirectly) into dmar_acpi_dev_scope_init() which uses the
dmar_tbl pointer without any checks.

The AMD IOMMU driver also sets the irq_remapping_enabled
flag which causes the dmar_acpi_dev_scope_init() function to
be called on systems with AMD IOMMU hardware too, causing a
boot-time kernel crash.

Signed-off-by: Joerg Roedel <joro@8bytes.org>

parent cf04eee8

drivers/iommu/dmar.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -657,7 +657,12 @@ static void __init dmar_acpi_insert_dev_scope(u8 device_number,

		static int __init dmar_acpi_dev_scope_init(void)
		{
		struct acpi_dmar_andd andd = (void )dmar_tbl + sizeof(struct acpi_table_dmar);
		struct acpi_dmar_andd *andd;

		if (dmar_tbl == NULL)
		return -ENODEV;

		andd = (void *)dmar_tbl + sizeof(struct acpi_table_dmar);

		while (((unsigned long)andd) <
		((unsigned long)dmar_tbl) + dmar_tbl->length) {