From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54917) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y1xYU-0002ZP-MT for qemu-devel@nongnu.org; Fri, 19 Dec 2014 08:25:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y1xYO-0002eb-5J for qemu-devel@nongnu.org; Fri, 19 Dec 2014 08:25:18 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56254) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y1xYN-0002eK-Uq for qemu-devel@nongnu.org; Fri, 19 Dec 2014 08:25:12 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id sBJDPBFn013082 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Fri, 19 Dec 2014 08:25:11 -0500 From: Amos Kong Date: Fri, 19 Dec 2014 21:25:02 +0800 Message-Id: <1418995502-14908-1-git-send-email-akong@redhat.com> Subject: [Qemu-devel] [PATCH] check return value of fcntl() to detect invalid fd List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: jasowang@redhat.com, stefanha@redhat.com, mst@redhat.com Passing some invalid fds in QEMU commandline, the fds don't exist. QEMU will get error "TUNGETIFF ioctl() failed: Bad file descriptor", and coredump in setting queues. This patch checked return value of first operate to fd, QEMU will report error and exit without coredump. It's effected for both netdev fds and vhost_net fds. Signed-off-by: Amos Kong --- net/tap.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/net/tap.c b/net/tap.c index bde6b58..039280a 100644 --- a/net/tap.c +++ b/net/tap.c @@ -688,7 +688,7 @@ int net_init_tap(const NetClientOptions *opts, const char *name, NetClientState *peer) { const NetdevTapOptions *tap; - int fd, vnet_hdr = 0, i = 0, queues; + int fd, vnet_hdr = 0, i = 0, queues, ret; /* for the no-fd, no-helper case */ const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */ const char *downscript = NULL; @@ -722,7 +722,12 @@ int net_init_tap(const NetClientOptions *opts, const char *name, return -1; } - fcntl(fd, F_SETFL, O_NONBLOCK); + ret = fcntl(fd, F_SETFL, O_NONBLOCK); + if (ret < 0) { + error_report("Fail to set file status to nonblock, " + "%s", strerror(-ret)); + return -1; + } vnet_hdr = tap_probe_vnet_hdr(fd); @@ -761,7 +766,12 @@ int net_init_tap(const NetClientOptions *opts, const char *name, return -1; } - fcntl(fd, F_SETFL, O_NONBLOCK); + ret = fcntl(fd, F_SETFL, O_NONBLOCK); + if (ret < 0) { + error_report("Fail to set file status to nonblock, " + "%s", strerror(-ret)); + return -1; + } if (i == 0) { vnet_hdr = tap_probe_vnet_hdr(fd); -- 2.1.0