nfc_llcp_sock_get() takes a reference on the LLCP socket via sock_hold().
In nfc_llcp_recv_hdlc(), the LLCP_CLOSED branch releases the socket lock and drops the reference, but the function continues to operate on llcp_sock/sk and later runs release_sock() and nfc_llcp_sock_put() again on the common exit path.
Return immediately after the CLOSED cleanup to avoid refcount/lock imbalance and to avoid using the socket after dropping the reference.
Reported-by: Qianchang Zhao pioooooooooip@gmail.com Reported-by: Zhitong Liu liuzhitong1993@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Qianchang Zhao pioooooooooip@gmail.com --- net/nfc/llcp_core.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c index beeb3b4d2..be01ec9f4 100644 --- a/net/nfc/llcp_core.c +++ b/net/nfc/llcp_core.c @@ -1089,6 +1089,7 @@ static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local, if (sk->sk_state == LLCP_CLOSED) { release_sock(sk); nfc_llcp_sock_put(llcp_sock); + return; }
/* Pass the payload upstream */