From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45414) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cWh8m-0001PW-5S for qemu-devel@nongnu.org; Thu, 26 Jan 2017 05:18:56 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cWh8l-0005zw-9V for qemu-devel@nongnu.org; Thu, 26 Jan 2017 05:18:52 -0500 From: "Daniel P. Berrange" Date: Thu, 26 Jan 2017 10:18:13 +0000 Message-Id: <20170126101827.22378-5-berrange@redhat.com> In-Reply-To: <20170126101827.22378-1-berrange@redhat.com> References: <20170126101827.22378-1-berrange@redhat.com> Subject: [Qemu-devel] [PATCH v3 04/18] qcow: require image size to be > 1 for new images List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, Max Reitz , Kevin Wolf , "Daniel P. Berrange" The qcow driver refuses to open images which are less than 2 bytes in size, but will happily create such images. Add a check in the create path to avoid this discrepancy. Reviewed-by: Max Reitz Signed-off-by: Daniel P. Berrange --- block/qcow.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/block/qcow.c b/block/qcow.c index 7540f43..101c973 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -799,6 +799,12 @@ static int qcow_create(const char *filename, QemuOpts *opts, Error **errp) /* Read out options */ total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), BDRV_SECTOR_SIZE); + if (total_size <= 1) { + error_setg(errp, "Image size is too small, cannot be zero length"); + ret = -EINVAL; + goto cleanup; + } + backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); if (qemu_opt_get_bool_del(opts, BLOCK_OPT_ENCRYPT, false)) { flags |= BLOCK_FLAG_ENCRYPT; -- 2.9.3