From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60320) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V9GGo-0005Oy-Kp for qemu-devel@nongnu.org; Tue, 13 Aug 2013 11:12:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V9GGe-0003yp-PH for qemu-devel@nongnu.org; Tue, 13 Aug 2013 11:12:26 -0400 Sender: fluxion From: Michael Roth Date: Tue, 13 Aug 2013 10:10:51 -0500 Message-Id: <1376406680-16302-28-git-send-email-mdroth@linux.vnet.ibm.com> In-Reply-To: <1376406680-16302-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1376406680-16302-1-git-send-email-mdroth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 27/56] qapi: qapi-commands: fix possible leaks on visitor dealloc List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: aliguori@us.ibm.com, qemu-stable@nongnu.org From: Luiz Capitulino In qmp-marshal.c the dealloc visitor calls use the same errp pointer of the input visitor calls. This means that if any of the input visitor calls fails, then the dealloc visitor will return early, before freeing the object's memory. Here's an example, consider this code: int qmp_marshal_input_block_passwd(Monitor *mon, const QDict *qdict, QObject **ret) { [...] char * device = NULL; char * password = NULL; mi = qmp_input_visitor_new_strict(QOBJECT(args)); v = qmp_input_get_visitor(mi); visit_type_str(v, &device, "device", errp); visit_type_str(v, &password, "password", errp); qmp_input_visitor_cleanup(mi); if (error_is_set(errp)) { goto out; } qmp_block_passwd(device, password, errp); out: md = qapi_dealloc_visitor_new(); v = qapi_dealloc_get_visitor(md); visit_type_str(v, &device, "device", errp); visit_type_str(v, &password, "password", errp); qapi_dealloc_visitor_cleanup(md); [...] return 0; } Consider errp != NULL when the out label is reached, we're going to leak device and password. This patch fixes this by always passing errp=NULL for dealloc visitors, meaning that we always try to free them regardless of any previous failure. The above example would then be: out: md = qapi_dealloc_visitor_new(); v = qapi_dealloc_get_visitor(md); visit_type_str(v, &device, "device", NULL); visit_type_str(v, &password, "password", NULL); qapi_dealloc_visitor_cleanup(md); Signed-off-by: Luiz Capitulino Reviewed-by: Laszlo Ersek Reviewed-by: Michael Roth (cherry picked from commit 8f91ad8a1b4702966d91ea58cd90bbde1faea1b3) Signed-off-by: Michael Roth --- scripts/qapi-commands.py | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py index e06332b..b12b696 100644 --- a/scripts/qapi-commands.py +++ b/scripts/qapi-commands.py @@ -128,12 +128,15 @@ bool has_%(argname)s = false; def gen_visitor_input_block(args, obj, dealloc=False): ret = "" + errparg = 'errp' + if len(args) == 0: return ret push_indent() if dealloc: + errparg = 'NULL' ret += mcgen(''' md = qapi_dealloc_visitor_new(); v = qapi_dealloc_get_visitor(md); @@ -148,22 +151,22 @@ v = qmp_input_get_visitor(mi); for argname, argtype, optional, structured in parse_args(args): if optional: ret += mcgen(''' -visit_start_optional(v, &has_%(c_name)s, "%(name)s", errp); +visit_start_optional(v, &has_%(c_name)s, "%(name)s", %(errp)s); if (has_%(c_name)s) { ''', - c_name=c_var(argname), name=argname) + c_name=c_var(argname), name=argname, errp=errparg) push_indent() ret += mcgen(''' -%(visitor)s(v, &%(c_name)s, "%(name)s", errp); +%(visitor)s(v, &%(c_name)s, "%(name)s", %(errp)s); ''', c_name=c_var(argname), name=argname, argtype=argtype, - visitor=type_visitor(argtype)) + visitor=type_visitor(argtype), errp=errparg) if optional: pop_indent() ret += mcgen(''' } -visit_end_optional(v, errp); -''') +visit_end_optional(v, %(errp)s); +''', errp=errparg) if dealloc: ret += mcgen(''' @@ -194,7 +197,7 @@ static void qmp_marshal_output_%(c_name)s(%(c_ret_type)s ret_in, QObject **ret_o } qmp_output_visitor_cleanup(mo); v = qapi_dealloc_get_visitor(md); - %(visitor)s(v, &ret_in, "unused", errp); + %(visitor)s(v, &ret_in, "unused", NULL); qapi_dealloc_visitor_cleanup(md); } ''', -- 1.7.9.5