sony-laptop: fix early NULL pointer dereference
The SNC acpi driver could get early notifications before it fully
initializes and that could lead to dereferencing the sony_nc_handles
structure pointer that is still NULL at that stage.
Make sure we return early from the handle lookup function in these
cases.
Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index e642f5f..33c3b8c 100644
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -808,6 +808,11 @@
static int sony_find_snc_handle(int handle)
{
int i;
+
+ /* not initialized yet, return early */
+ if (!handles)
+ return -1;
+
for (i = 0; i < 0x10; i++) {
if (handles->cap[i] == handle) {
dprintk("found handle 0x%.4x (offset: 0x%.2x)\n",