[PATCH] HID: logitech: perform bounds checking on device_id early enough
From: Jiri Kosina <hidden>
Date: 2014-08-21 15:45:30
Also in:
lkml
Subsystem:
hid core layer, hid logitech drivers, the rest · Maintainers:
Jiri Kosina, Benjamin Tissoires, Linus Torvalds
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@vger.kernel.org Reported-by: Ben Hawkes <redacted> Reviewed-by: Benjamin Tissoires <redacted> Signed-off-by: Jiri Kosina <redacted> --- 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