From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Daley Subject: [PATCH 08/13 v5] libxl: don't leak ptr in libxl_list_vm error case Date: Tue, 3 Dec 2013 14:29:04 +1300 Message-ID: <1386034144-9572-1-git-send-email-mattd@bugfuzz.com> References: <21148.41308.706376.518540@mariner.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <21148.41308.706376.518540@mariner.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: Andrew Cooper , Matthew Daley , Ian Jackson , Ian Campbell , Stefano Stabellini List-Id: xen-devel@lists.xenproject.org While at it, tidy up the function; there's no point in allocating more than the amount of domains actually returned by xc_domain_getinfolist (barring the caveat described in the newly-added comment) Coverity-ID: 1055888 Signed-off-by: Matthew Daley --- v5: Use libxl__calloc instead of calloc tools/libxl/libxl.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c index 67a8e0e..3b73d99 100644 --- a/tools/libxl/libxl.c +++ b/tools/libxl/libxl.c @@ -671,20 +671,24 @@ out: * be an aggregate of multiple domains. */ libxl_vminfo * libxl_list_vm(libxl_ctx *ctx, int *nb_vm_out) { - libxl_vminfo *ptr; + GC_INIT(ctx); + libxl_vminfo *ptr = NULL; int idx, i, ret; xc_domaininfo_t info[1024]; - int size = 1024; - ptr = calloc(size, sizeof(libxl_vminfo)); - if (!ptr) - return NULL; - - ret = xc_domain_getinfolist(ctx->xch, 1, 1024, info); - if (ret<0) { - LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "geting domain info list"); - return NULL; + ret = xc_domain_getinfolist(ctx->xch, 1, ARRAY_SIZE(info), info); + if (ret < 0) { + LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "getting domain info list"); + goto out; } + + /* + * Always make sure to allocate at least one element; if we don't and we + * request zero, libxl__calloc (might) think its internal call to calloc + * has failed (if it returns null), if so it would kill our process. + */ + ptr = libxl__calloc(NOGC, ret ? ret : 1, sizeof(libxl_vminfo)); + for (idx = i = 0; i < ret; i++) { if (libxl_is_stubdom(ctx, info[i].domain, NULL)) continue; @@ -694,6 +698,9 @@ libxl_vminfo * libxl_list_vm(libxl_ctx *ctx, int *nb_vm_out) idx++; } *nb_vm_out = idx; + +out: + GC_FREE; return ptr; } -- 1.7.10.4