From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45014) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fSGwr-0001Fn-2x for qemu-devel@nongnu.org; Mon, 11 Jun 2018 03:09:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fSGwl-0003RE-It for qemu-devel@nongnu.org; Mon, 11 Jun 2018 03:09:05 -0400 Received: from mail-pf0-x244.google.com ([2607:f8b0:400e:c00::244]:46315) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fSGwl-0003QW-Bu for qemu-devel@nongnu.org; Mon, 11 Jun 2018 03:08:59 -0400 Received: by mail-pf0-x244.google.com with SMTP id q1-v6so9720095pff.13 for ; Mon, 11 Jun 2018 00:08:59 -0700 (PDT) Sender: Lin Ma From: Lin Ma Date: Mon, 11 Jun 2018 15:06:09 +0800 Message-Id: <20180611070609.9482-1-lma@suse.com> Subject: [Qemu-devel] [PATCH v2] net: Fix a potential segfault List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: thuth@redhat.com, jasowang@redhat.com, Lin Ma If user forgets to provide any backend types for '-netdev' in qemu CLI, It triggers seg fault. e.g. Expected: $ qemu -netdev id=net0 qemu-system-x86_64: Parameter 'type' is missing Actual: $ qemu -netdev id=net0 Segmentation fault (core dumped) Signed-off-by: Lin Ma --- net/net.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/net/net.c b/net/net.c index efb9eaf779..f89790be4a 100644 --- a/net/net.c +++ b/net/net.c @@ -1093,9 +1093,12 @@ static int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp) int ret = -1; Visitor *v = opts_visitor_new(opts); - if (is_netdev && is_help_option(qemu_opt_get(opts, "type"))) { - show_netdevs(); - exit(0); + if (is_netdev) { + const char *type = qemu_opt_get(opts, "type"); + if (type && is_help_option(type)) { + show_netdevs(); + exit(0); + } } else { /* Parse convenience option format ip6-net=fec0::0[/64] */ const char *ip6_net = qemu_opt_get(opts, "ipv6-net"); -- 2.16.2