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

8 Dec 2019

3.16.79-rc1 review patch.  If anyone has any objections, please let me know.
------------------
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)

    

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