[PATCH][next] acpi/hmat: fix uninitialized pointer dereference on pointer 'target'

From: Colin King
Date: Fri Apr 05 2019 - 10:12:22 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

The pointer 'target' is not initialized and is only assigned when the
ACPI_HMAT_MEMORY_PD_VALID bit in p->flags is set. There is a later null
check on target that leads to an uninitialized pointer read and
dereference when assigning target->processor_pxm when target contains a
non-null garbage value. Fix this by initializing targer to null.

Fixes: 665ac7e92757 ("acpi/hmat: Register processor domain to its memory")
Addresses-Coverity: ("Uninitialized pointer read")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/acpi/hmat/hmat.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/hmat/hmat.c b/drivers/acpi/hmat/hmat.c
index b7824a0309f7..b275016ff648 100644
--- a/drivers/acpi/hmat/hmat.c
+++ b/drivers/acpi/hmat/hmat.c
@@ -366,7 +366,7 @@ static int __init hmat_parse_proximity_domain(union acpi_subtable_headers *heade
const unsigned long end)
{
struct acpi_hmat_proximity_domain *p = (void *)header;
- struct memory_target *target;
+ struct memory_target *target = NULL;

if (p->header.length != sizeof(*p)) {
pr_notice("HMAT: Unexpected address range header length: %d\n",
--
2.20.1