diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2019-10-03 14:53:59 -0400 |
|---|---|---|
| committer | Benjamin Tissoires <benjamin.tissoires@redhat.com> | 2019-10-03 15:36:40 -0400 |
| commit | d9d4b1e46d9543a82c23f6df03f4ad697dab361b (patch) | |
| tree | 5a405a2f78b1029f4cc6d6ee743f0bec31319b42 /drivers/hid/hid-lg4ff.c | |
| parent | fe2199cfd1516e90e03c033c52c9a28da09d9986 (diff) | |
HID: Fix assumption that devices have inputs
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>
CC: <stable@vger.kernel.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Diffstat (limited to 'drivers/hid/hid-lg4ff.c')
| -rw-r--r-- | drivers/hid/hid-lg4ff.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c index 03f0220062ca..5e6a0cef2a06 100644 --- a/drivers/hid/hid-lg4ff.c +++ b/drivers/hid/hid-lg4ff.c @@ -1253,8 +1253,8 @@ static int lg4ff_handle_multimode_wheel(struct hid_device *hid, u16 *real_produc 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 list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list; struct hid_report *report = list_entry(report_list->next, struct hid_report, list); const struct usb_device_descriptor *udesc = &(hid_to_usb_dev(hid)->descriptor); @@ -1266,6 +1266,13 @@ int lg4ff_init(struct hid_device *hid) int mmode_ret, mmode_idx = -1; u16 real_product_id; + 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; |