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[2001:4830:134:3::11]) by mx.google.com with ESMTPS id a30si2115320qtb.307.2017.07.18.07.23.42 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 18 Jul 2017 07:23:43 -0700 (PDT) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) client-ip=2001:4830:134:3::11; Authentication-Results: mx.google.com; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-devel-bounces+patch=linaro.org@nongnu.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from localhost ([::1]:56809 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dXTPY-0004nR-PV for patch@linaro.org; Tue, 18 Jul 2017 10:23:40 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52942) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dXTKR-0000NE-RQ for qemu-devel@nongnu.org; Tue, 18 Jul 2017 10:18:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dXTKQ-0007a6-O7 for qemu-devel@nongnu.org; Tue, 18 Jul 2017 10:18:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59464) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dXTKN-0007Wh-V2; Tue, 18 Jul 2017 10:18:20 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E154FC04D294; Tue, 18 Jul 2017 14:18:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com E154FC04D294 Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=kwolf@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com E154FC04D294 Received: from noname.str.redhat.com (dhcp-192-175.str.redhat.com [10.33.192.175]) by smtp.corp.redhat.com (Postfix) with ESMTP id DA0DD7EF5F; Tue, 18 Jul 2017 14:18:17 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Tue, 18 Jul 2017 16:17:49 +0200 Message-Id: <1500387486-5469-5-git-send-email-kwolf@redhat.com> In-Reply-To: <1500387486-5469-1-git-send-email-kwolf@redhat.com> References: <1500387486-5469-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Tue, 18 Jul 2017 14:18:19 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 04/21] block/vmdk: Report failures in vmdk_read_cid() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patch=linaro.org@nongnu.org Sender: "Qemu-devel" From: Peter Maydell The function vmdk_read_cid() can fail if the read on the underlying block device fails, or if there's a format error in the VMDK file. However its API doesn't provide a mechanism to report these errors, and in some cases we were returning a CID of 0 and in some cases a CID of 0xffffffff, either of which might potentially be valid values. Change the function to return 0 on success or a negative errno, and return the CID via a uint32_t* argument. Update the callsites to handle and propagate the error appropriately. This fixes in passing a Coverity-spotted issue (CID 1350038) where we weren't checking the return value from sscanf(). Signed-off-by: Peter Maydell Reviewed-by: Fam Zheng Signed-off-by: Kevin Wolf --- block/vmdk.c | 44 ++++++++++++++++++++++++++++++++------------ 1 file changed, 32 insertions(+), 12 deletions(-) -- 1.8.3.1 diff --git a/block/vmdk.c b/block/vmdk.c index 24d71b5..0fc9739 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -242,10 +242,11 @@ static void vmdk_free_last_extent(BlockDriverState *bs) s->extents = g_renew(VmdkExtent, s->extents, s->num_extents); } -static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent) +/* Return -ve errno, or 0 on success and write CID into *pcid. */ +static int vmdk_read_cid(BlockDriverState *bs, int parent, uint32_t *pcid) { char *desc; - uint32_t cid = 0xffffffff; + uint32_t cid; const char *p_name, *cid_str; size_t cid_str_size; BDRVVmdkState *s = bs->opaque; @@ -254,8 +255,7 @@ static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent) desc = g_malloc0(DESC_SIZE); ret = bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE); if (ret < 0) { - g_free(desc); - return 0; + goto out; } if (parent) { @@ -268,13 +268,21 @@ static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent) desc[DESC_SIZE - 1] = '\0'; p_name = strstr(desc, cid_str); - if (p_name != NULL) { - p_name += cid_str_size; - sscanf(p_name, "%" SCNx32, &cid); + if (p_name == NULL) { + ret = -EINVAL; + goto out; } + p_name += cid_str_size; + if (sscanf(p_name, "%" SCNx32, &cid) != 1) { + ret = -EINVAL; + goto out; + } + *pcid = cid; + ret = 0; +out: g_free(desc); - return cid; + return ret; } static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid) @@ -322,7 +330,10 @@ static int vmdk_is_cid_valid(BlockDriverState *bs) if (!s->cid_checked && bs->backing) { BlockDriverState *p_bs = bs->backing->bs; - cur_pcid = vmdk_read_cid(p_bs, 0); + if (vmdk_read_cid(p_bs, 0, &cur_pcid) != 0) { + /* read failure: report as not valid */ + return 0; + } if (s->parent_cid != cur_pcid) { /* CID not valid */ return 0; @@ -975,8 +986,14 @@ static int vmdk_open(BlockDriverState *bs, QDict *options, int flags, if (ret) { goto fail; } - s->cid = vmdk_read_cid(bs, 0); - s->parent_cid = vmdk_read_cid(bs, 1); + ret = vmdk_read_cid(bs, 0, &s->cid); + if (ret) { + goto fail; + } + ret = vmdk_read_cid(bs, 1, &s->parent_cid); + if (ret) { + goto fail; + } qemu_co_mutex_init(&s->lock); /* Disable migration when VMDK images are used */ @@ -2008,8 +2025,11 @@ static int vmdk_create(const char *filename, QemuOpts *opts, Error **errp) ret = -EINVAL; goto exit; } - parent_cid = vmdk_read_cid(blk_bs(blk), 0); + ret = vmdk_read_cid(blk_bs(blk), 0, &parent_cid); blk_unref(blk); + if (ret) { + goto exit; + } snprintf(parent_desc_line, BUF_SIZE, "parentFileNameHint=\"%s\"", backing_file); }