[RESEND] HID: steam: Prevent NULL pointer dereference in steam_{recv,send}_report

Lee Jones
2022-08-03T11:18:54Z

It is possible for a malicious device to forgo submitting a Feature
Report. The HID Steam driver presently makes no prevision for this
and de-references the 'struct hid_report' pointer obtained from the
HID devices without first checking its validity. Let's change that.

Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: linux-input@vger.kernel.org
Fixes: c164d6abf3841 ("HID: add driver for Valve Steam Controller")
Signed-off-by: Lee Jones <lee@kernel.org>
---
drivers/hid/hid-steam.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/hid/hid-steam.c b/drivers/hid/hid-steam.c
index a3b151b29bd71..fc616db4231bb 100644
--- a/drivers/hid/hid-steam.c
+++ b/drivers/hid/hid-steam.c
@@ -134,6 +134,11 @@ static int steam_recv_report(struct steam_device *steam,
int ret;

r = steam->hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[0];
+ if (!r) {
+ hid_err(steam->hdev, "No HID_FEATURE_REPORT submitted - nothing to read\n");
+ return -EINVAL;
+ }
+
if (hid_report_len(r) < 64)
return -EINVAL;

@@ -165,6 +170,11 @@ static int steam_send_report(struct steam_device *steam,
int ret;

r = steam->hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[0];
+ if (!r) {
+ hid_err(steam->hdev, "No HID_FEATURE_REPORT submitted - nothing to read\n");
+ return -EINVAL;
+ }
+
if (hid_report_len(r) < 64)
return -EINVAL;

--
2.37.1.455.g008518b4e5-goog