[PATCH 3/4] platform/x86: dell-wmi-base: Fix handling of ultra performance key

[Armin Wolf]

The commit message of commit 5fbd827eb9c2 ("platform/x86: dell-wmi: Recognise or support new switches")
states that the ultra performance key contains additional data
after the type and code fields. The event data passed to
dell_wmi_process_key() is already parsed, so "buffer" already
starts after those two fields.

Use the correct index for accessing the first data field to avoid
a potential buffer overread.

Fixes: 5fbd827eb9c2 ("platform/x86: dell-wmi: Recognise or support new switches")
Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
---
 drivers/platform/x86/dell/dell-wmi-base.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/x86/dell/dell-wmi-base.c b/drivers/platform/x86/dell/dell-wmi-base.c
index fd6a508cd902..38a6b3ae2f75 100644
--- a/drivers/platform/x86/dell/dell-wmi-base.c
+++ b/drivers/platform/x86/dell/dell-wmi-base.c
@@ -456,7 +456,7 @@ static int dell_wmi_process_key(struct wmi_device *wdev, int type, int code, __l
 			key++;
 		used = 1;
 	} else if (type == 0x0012 && code == 0x000d && remaining > 0) {
-		value = (le16_to_cpu(buffer[2]) == 2);
+		value = (le16_to_cpu(buffer[0]) == 2);
 		used = 1;
 	}
 
-- 
2.39.5