HID: Fix assumption that devices have inputs

commit d9d4b1e46d9543a82c23f6df03f4ad697dab361b upstream.

The syzbot fuzzer found a slab-out-of-bounds write bug in the hid-gaff
driver.  The problem is caused by the driver's assumption that the
device must have an input report.  While this will be true for all
normal HID input devices, a suitably malicious device can violate the
assumption.

The same assumption is present in over a dozen other HID drivers.
This patch fixes them by checking that the list of hid_inputs for the
hid_device is nonempty before allowing it to be used.

Issue: SEC-2293
Reported-and-tested-by: syzbot+403741a091bf41d4ae79@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
[bwh: Backported to 3.16:
 - Drop changes in hid-logitech-hidpp, hid-microsoft
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[Backported to FP2/3.4:
 - hid-sony is dropped from the FP2 kernel]
(cherry picked from commit f703c175f8e428959a33cdadb3e09986f14390ce)
Change-Id: Id22f6fa6150fb3e9199798a73cde86ce26708c17
diff --git a/drivers/hid/hid-axff.c b/drivers/hid/hid-axff.c
index 5be858d..e35c3ac 100644
--- a/drivers/hid/hid-axff.c
+++ b/drivers/hid/hid-axff.c
@@ -77,13 +77,20 @@
 {
 	struct axff_device *axff;
 	struct hid_report *report;
-	struct hid_input *hidinput = list_first_entry(&hid->inputs, struct hid_input, list);
+	struct hid_input *hidinput;
 	struct list_head *report_list =&hid->report_enum[HID_OUTPUT_REPORT].report_list;
-	struct input_dev *dev = hidinput->input;
+	struct input_dev *dev;
 	int field_count = 0;
 	int i, j;
 	int error;
 
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+	hidinput = list_first_entry(&hid->inputs, struct hid_input, list);
+	dev = hidinput->input;
+
 	if (list_empty(report_list)) {
 		hid_err(hid, "no output reports found\n");
 		return -ENODEV;
diff --git a/drivers/hid/hid-dr.c b/drivers/hid/hid-dr.c
index e832f44..523bbda 100644
--- a/drivers/hid/hid-dr.c
+++ b/drivers/hid/hid-dr.c
@@ -89,13 +89,19 @@
 {
 	struct drff_device *drff;
 	struct hid_report *report;
-	struct hid_input *hidinput = list_first_entry(&hid->inputs,
-						struct hid_input, list);
+	struct hid_input *hidinput;
 	struct list_head *report_list =
 			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
-	struct input_dev *dev = hidinput->input;
+	struct input_dev *dev;
 	int error;
 
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+	hidinput = list_first_entry(&hid->inputs, struct hid_input, list);
+	dev = hidinput->input;
+
 	if (list_empty(report_list)) {
 		hid_err(hid, "no output reports found\n");
 		return -ENODEV;
diff --git a/drivers/hid/hid-emsff.c b/drivers/hid/hid-emsff.c
index 2630d48..7ac635d 100644
--- a/drivers/hid/hid-emsff.c
+++ b/drivers/hid/hid-emsff.c
@@ -61,13 +61,19 @@
 {
 	struct emsff_device *emsff;
 	struct hid_report *report;
-	struct hid_input *hidinput = list_first_entry(&hid->inputs,
-						struct hid_input, list);
+	struct hid_input *hidinput;
 	struct list_head *report_list =
 			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
-	struct input_dev *dev = hidinput->input;
+	struct input_dev *dev;
 	int error;
 
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+	hidinput = list_first_entry(&hid->inputs, struct hid_input, list);
+	dev = hidinput->input;
+
 	if (list_empty(report_list)) {
 		hid_err(hid, "no output reports found\n");
 		return -ENODEV;
diff --git a/drivers/hid/hid-gaff.c b/drivers/hid/hid-gaff.c
index f1e1bcf..f7c74d5 100644
--- a/drivers/hid/hid-gaff.c
+++ b/drivers/hid/hid-gaff.c
@@ -79,14 +79,20 @@
 {
 	struct gaff_device *gaff;
 	struct hid_report *report;
-	struct hid_input *hidinput = list_entry(hid->inputs.next,
-						struct hid_input, list);
+	struct hid_input *hidinput;
 	struct list_head *report_list =
 			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
 	struct list_head *report_ptr = report_list;
-	struct input_dev *dev = hidinput->input;
+	struct input_dev *dev;
 	int error;
 
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+	dev = hidinput->input;
+
 	if (list_empty(report_list)) {
 		hid_err(hid, "no output reports found\n");
 		return -ENODEV;
diff --git a/drivers/hid/hid-holtekff.c b/drivers/hid/hid-holtekff.c
index 4e75421..8797e696 100644
--- a/drivers/hid/hid-holtekff.c
+++ b/drivers/hid/hid-holtekff.c
@@ -143,13 +143,19 @@
 {
 	struct holtekff_device *holtekff;
 	struct hid_report *report;
-	struct hid_input *hidinput = list_entry(hid->inputs.next,
-						struct hid_input, list);
+	struct hid_input *hidinput;
 	struct list_head *report_list =
 			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
-	struct input_dev *dev = hidinput->input;
+	struct input_dev *dev;
 	int error;
 
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+	dev = hidinput->input;
+
 	if (list_empty(report_list)) {
 		hid_err(hid, "no output report found\n");
 		return -ENODEV;
diff --git a/drivers/hid/hid-lg2ff.c b/drivers/hid/hid-lg2ff.c
index 128f011..a59553a 100644
--- a/drivers/hid/hid-lg2ff.c
+++ b/drivers/hid/hid-lg2ff.c
@@ -64,11 +64,17 @@
 {
 	struct lg2ff_device *lg2ff;
 	struct hid_report *report;
-	struct hid_input *hidinput = list_entry(hid->inputs.next,
-						struct hid_input, list);
-	struct input_dev *dev = hidinput->input;
+	struct hid_input *hidinput;
+	struct input_dev *dev;
 	int error;
 
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+	dev = hidinput->input;
+
 	/* Check that the report looks ok */
 	report = hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 7);
 	if (!report)
diff --git a/drivers/hid/hid-lg3ff.c b/drivers/hid/hid-lg3ff.c
index 91f981f..18de3ed 100644
--- a/drivers/hid/hid-lg3ff.c
+++ b/drivers/hid/hid-lg3ff.c
@@ -131,12 +131,19 @@
 
 int lg3ff_init(struct hid_device *hid)
 {
-	struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
-	struct input_dev *dev = hidinput->input;
+	struct hid_input *hidinput;
+	struct input_dev *dev;
 	const signed short *ff_bits = ff3_joystick_ac;
 	int error;
 	int i;
 
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+	dev = hidinput->input;
+
 	/* Check that the report looks ok */
 	if (!hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 35))
 		return -ENODEV;
diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
index 44bb0a5..8917837 100644
--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c
@@ -338,13 +338,20 @@
 
 int lg4ff_init(struct hid_device *hid)
 {
-	struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
-	struct input_dev *dev = hidinput->input;
+	struct hid_input *hidinput;
+	struct input_dev *dev;
 	struct lg4ff_device_entry *entry;
 	struct usb_device_descriptor *udesc;
 	int error, i, j;
 	__u16 bcdDevice, rev_maj, rev_min;
 
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+	dev = hidinput->input;
+
 	/* Check that the report looks ok */
 	if (!hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 7))
 		return -1;
diff --git a/drivers/hid/hid-lgff.c b/drivers/hid/hid-lgff.c
index 1d978daa..94c492a 100644
--- a/drivers/hid/hid-lgff.c
+++ b/drivers/hid/hid-lgff.c
@@ -129,12 +129,19 @@
 
 int lgff_init(struct hid_device* hid)
 {
-	struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
-	struct input_dev *dev = hidinput->input;
+	struct hid_input *hidinput;
+	struct input_dev *dev;
 	const signed short *ff_bits = ff_joystick;
 	int error;
 	int i;
 
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+	dev = hidinput->input;
+
 	/* Check that the report looks ok */
 	if (!hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 7))
 		return -ENODEV;
diff --git a/drivers/hid/hid-tmff.c b/drivers/hid/hid-tmff.c
index 83a933b..8a4d839 100644
--- a/drivers/hid/hid-tmff.c
+++ b/drivers/hid/hid-tmff.c
@@ -128,12 +128,18 @@
 	struct tmff_device *tmff;
 	struct hid_report *report;
 	struct list_head *report_list;
-	struct hid_input *hidinput = list_entry(hid->inputs.next,
-							struct hid_input, list);
-	struct input_dev *input_dev = hidinput->input;
+	struct hid_input *hidinput;
+	struct input_dev *input_dev;
 	int error;
 	int i;
 
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+	input_dev = hidinput->input;
+
 	tmff = kzalloc(sizeof(struct tmff_device), GFP_KERNEL);
 	if (!tmff)
 		return -ENOMEM;
diff --git a/drivers/hid/hid-zpff.c b/drivers/hid/hid-zpff.c
index f348f7f..4ffa681 100644
--- a/drivers/hid/hid-zpff.c
+++ b/drivers/hid/hid-zpff.c
@@ -68,11 +68,17 @@
 {
 	struct zpff_device *zpff;
 	struct hid_report *report;
-	struct hid_input *hidinput = list_entry(hid->inputs.next,
-						struct hid_input, list);
-	struct input_dev *dev = hidinput->input;
+	struct hid_input *hidinput;
+	struct input_dev *dev;
 	int i, error;
 
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+	dev = hidinput->input;
+
 	for (i = 0; i < 4; i++) {
 		report = hid_validate_values(hid, HID_OUTPUT_REPORT, 0, i, 1);
 		if (!report)