[PATCH 3.16 70/72] HID: Fix assumption that devices have inputs

Ben Hutchings
2019-12-08T13:55:28Z

From: Alan Stern <stern@rowland.harvard.edu>

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.

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>
---
--- a/drivers/hid/hid-axff.c
+++ b/drivers/hid/hid-axff.c
@@ -75,13 +75,20 @@ static int axff_init(struct hid_device *
{
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;
--- a/drivers/hid/hid-dr.c
+++ b/drivers/hid/hid-dr.c
@@ -87,13 +87,19 @@ static int drff_init(struct hid_device *
{
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;
--- a/drivers/hid/hid-emsff.c
+++ b/drivers/hid/hid-emsff.c
@@ -59,13 +59,19 @@ static int emsff_init(struct hid_device
{
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;
--- a/drivers/hid/hid-gaff.c
+++ b/drivers/hid/hid-gaff.c
@@ -77,14 +77,20 @@ static int gaff_init(struct hid_device *
{
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;
--- a/drivers/hid/hid-holtekff.c
+++ b/drivers/hid/hid-holtekff.c
@@ -140,13 +140,19 @@ static int holtekff_init(struct hid_devi
{
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;
--- a/drivers/hid/hid-lg2ff.c
+++ b/drivers/hid/hid-lg2ff.c
@@ -62,11 +62,17 @@ int lg2ff_init(struct hid_device *hid)
{
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)
--- a/drivers/hid/hid-lg3ff.c
+++ b/drivers/hid/hid-lg3ff.c
@@ -129,12 +129,19 @@ static const signed short ff3_joystick_a

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;
--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c
@@ -558,14 +558,21 @@ static enum led_brightness lg4ff_led_get

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 lg_drv_data *drv_data;
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;
--- a/drivers/hid/hid-lgff.c
+++ b/drivers/hid/hid-lgff.c
@@ -127,12 +127,19 @@ static void hid_lgff_set_autocenter(stru

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;
--- a/drivers/hid/hid-sony.c
+++ b/drivers/hid/hid-sony.c
@@ -1509,9 +1509,15 @@ static int sony_play_effect(struct input

static int sony_init_ff(struct sony_sc *sc)
{
- struct hid_input *hidinput = list_entry(sc->hdev->inputs.next,
- struct hid_input, list);
- struct input_dev *input_dev = hidinput->input;
+ struct hid_input *hidinput;
+ struct input_dev *input_dev;
+
+ if (list_empty(&sc->hdev->inputs)) {
+ hid_err(sc->hdev, "no inputs found\n");
+ return -ENODEV;
+ }
+ hidinput = list_entry(sc->hdev->inputs.next, struct hid_input, list);
+ input_dev = hidinput->input;

input_set_capability(input_dev, EV_FF, FF_RUMBLE);
return input_ff_create_memless(input_dev, NULL, sony_play_effect);
--- a/drivers/hid/hid-tmff.c
+++ b/drivers/hid/hid-tmff.c
@@ -126,12 +126,18 @@ static int tmff_init(struct hid_device *
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;
--- a/drivers/hid/hid-zpff.c
+++ b/drivers/hid/hid-zpff.c
@@ -66,11 +66,17 @@ static int zpff_init(struct hid_device *
{
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)