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>
This commit is contained in:
Joerg Roedel 2014-03-25 20:16:40 +01:00
parent cf04eee8bf
commit 11f1a7768c
1 changed files with 6 additions and 1 deletions

View File

@ -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) {