From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [PATCH net] vhost_net: validate sock before trying to put its fd Date: Thu, 21 Jun 2018 13:11:31 +0800 Message-ID: <1529557891-4828-1-git-send-email-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: dan.carpenter@oracle.com To: mst@redhat.com, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org Sock will be NULL if we pass -1 to vhost_net_set_backend(), but when we meet errors during ubuf allocation, the code does not check for NULL before calling sockfd_put(), this will lead NULL dereferencing. Fixing by checking sock pointer before. Fixes: bab632d69ee4 ("vhost: vhost TX zero-copy support") Reported-by: Dan Carpenter Signed-off-by: Jason Wang --- drivers/vhost/net.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 986058a..b97a994 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -1208,7 +1208,8 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) if (ubufs) vhost_net_ubuf_put_wait_and_free(ubufs); err_ubufs: - sockfd_put(sock); + if (sock) + sockfd_put(sock); err_vq: mutex_unlock(&vq->mutex); err: -- 2.7.4