VMCI: Fix deref before NULL-check of queuepair ptr

Check for a valid queuepair ptr before trying to lock the queuepair (which will
deref it).

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andy King <acking@vmware.com>
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c
index da47e457e158d27f6251946e10e357824aee7c59..6417a26df8d861370c115414cc5b8e5de10c868d 100644 (file)
--- a/drivers/misc/vmw_vmci/vmci_queue_pair.c
+++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c
@@ -3355,11 +3355,11 @@ ssize_t vmci_qpair_dequev(struct vmci_qp *qpair,
 {
        ssize_t result;
 
-       qp_lock(qpair);
-
        if (!qpair || !iov)
                return VMCI_ERROR_INVALID_ARGS;
 
+       qp_lock(qpair);
+
        do {
                result = qp_dequeue_locked(qpair->produce_q,
                                           qpair->consume_q,