net:nfc:digital: Fix a double free in digital_tg_recv_dep_req

In digital_tg_recv_dep_req, it calls nfc_tm_data_received(..,resp).
If nfc_tm_data_received() failed, the callee will free the resp via
kfree_skb() and return error. But in the exit branch, the resp
will be freed again.

My patch sets resp to NULL if nfc_tm_data_received() failed, to
avoid the double free.

Fixes: 1c7a4c24fbfd9 ("NFC Digital: Add target NFC-DEP support")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c
index 1150731..3982fa0 100644 (file)
--- a/net/nfc/digital_dep.c
+++ b/net/nfc/digital_dep.c
@@ -1273,6 +1273,8 @@ static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
        }
 
        rc = nfc_tm_data_received(ddev->nfc_dev, resp);
+       if (rc)
+               resp = NULL;
 
 exit:
        kfree_skb(ddev->chaining_skb);