NFC: st21nfca: Add condition to make sure atr_req->length is valid.
gb_len in st21nfca_tm_send_atr_res can be negative. Not checking for
that could lead to a potential kernel oops.
We now make sure that atr_req->length > sizeof(struct st21nfca_atr_req)
to avoid such situation.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/nfc/st21nfca/st21nfca_dep.c b/drivers/nfc/st21nfca/st21nfca_dep.c
index b6de27b..6c09a66 100644
--- a/drivers/nfc/st21nfca/st21nfca_dep.c
+++ b/drivers/nfc/st21nfca/st21nfca_dep.c
@@ -211,6 +211,11 @@
atr_req = (struct st21nfca_atr_req *)skb->data;
+ if (atr_req->length < sizeof(struct st21nfca_atr_req)) {
+ r = -EPROTO;
+ goto exit;
+ }
+
r = st21nfca_tm_send_atr_res(hdev, atr_req);
if (r)
goto exit;
