device_index is a char type and the size of paired_dj_deivces is 7
elements, therefore proper bounds checking has to be applied to
device_index before it is used.
We are currently performing the bounds checking in
logi_dj_recv_add_djhid_device(), which is too late, as malicious device
could send REPORT_TYPE_NOTIF_DEVICE_UNPAIRED early enough and trigger the
problem in one of the report forwarding functions called from
logi_dj_raw_event().
Fix this by performing the check at the earliest possible ocasion in
logi_dj_raw_event().
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Ben Hawkes <hawkes@xxxxxxxxxx>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
---
drivers/hid/hid-logitech-dj.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
index ca0ab51..b7ba829 100644
--- a/drivers/hid/hid-logitech-dj.c
+++ b/drivers/hid/hid-logitech-dj.c
@@ -238,13 +238,6 @@ static void logi_dj_recv_add_djhid_device(struct dj_receiver_dev *djrcv_dev,
return;
}
- if ((dj_report->device_index < DJ_DEVICE_INDEX_MIN) ||
- (dj_report->device_index > DJ_DEVICE_INDEX_MAX)) {
- dev_err(&djrcv_hdev->dev, "%s: invalid device index:%d\n",
- __func__, dj_report->device_index);
- return;
- }
-
if (djrcv_dev->paired_dj_devices[dj_report->device_index]) {
/* The device is already known. No need to reallocate it. */
dbg_hid("%s: device is already known\n", __func__);
@@ -690,6 +683,12 @@ static int logi_dj_raw_event(struct hid_device *hdev,
* device (via hid_input_report() ) and return 1 so hid-core does not do
* anything else with it.
*/
+ if ((dj_report->device_index < DJ_DEVICE_INDEX_MIN) ||
+ (dj_report->device_index > DJ_DEVICE_INDEX_MAX)) {
+ dev_err(&hdev->dev, "%s: invalid device index:%d\n",
+ __func__, dj_report->device_index);
+ return false;
+ }
spin_lock_irqsave(&djrcv_dev->lock, flags);
if (dj_report->report_id == REPORT_ID_DJ_SHORT) {
--
Jiri Kosina
SUSE Labs
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