On 06/30/2014 12:30 PM, Lukas Slebodnik wrote:
On (30/06/14 11:24), Pavel Březina wrote:
> On 06/26/2014 07:28 AM, Lukas Slebodnik wrote:
>> ehlo,
>>
>> there is a bunch of error reported from static analysers
>> Dereferencing a pointer that might be null "error" when calling
>> "sbus_request_fail_and_finish"
>>
>> similar problem is with dereferencing NULL pointer in function
>> sbus_request_invoke_or_finish.
>>
>> These situation can happen mostly with handling errors.
>>
>> LS
>
> Hi,
> the attached patch should fix it.
>
>From d021b2302ff64798497cc08969fa328183e3063e Mon Sep 17 00:00:00 2001
> From: =?UTF-8?q?Pavel=20B=C5=99ezina?= <pbrezina(a)redhat.com>
> Date: Mon, 30 Jun 2014 11:23:21 +0200
> Subject: [PATCH] sbus_request: fix potential NULL dereference
>
> ---
> src/sbus/sssd_dbus_request.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/src/sbus/sssd_dbus_request.c b/src/sbus/sssd_dbus_request.c
> index
2852f87d833d448e330fb36525083c4c8eb78605..c39a6a4afc4af36c044995ad30bfd2c32fe32d8b 100644
> --- a/src/sbus/sssd_dbus_request.c
> +++ b/src/sbus/sssd_dbus_request.c
> @@ -63,10 +63,12 @@ sbus_request_invoke_or_finish(struct sbus_request *dbus_req,
> DBusError error;
> int ret;
>
> - if (invoker_fn) {
> + if (handler_fn != NULL && invoker_fn != NULL) {
> ret = invoker_fn(dbus_req, handler_fn);
> - } else {
> + } else if (handler_fn != NULL) {
> ret = handler_fn(dbus_req, handler_data);
> + } else {
> + ret = EINVAL;
> }
I agree it is better to return EINVAL instead of crash, but I wonder why NULL
is used as hadler_fn and handler data isn't NULL/
Probably it was not clear from very long list of warnings in my 1st mail.
src/sbus/sssd_dbus_properties.c:361: sbus_request_invoke_or_finish(req, NULL,
src/sbus/sssd_dbus_properties.c-362-
intf->instance_data,
src/sbus/sssd_dbus_properties.c-363-
meta->invoker_get_all);
src/sbus/sssd_dbus_properties.c-364- return EOK;
src/sbus/sssd_dbus_properties.c-365-}
I guess it is a relic from copy and paste, since invokers access handler
data directly through sbus_request. I think it would be more clear to
also pass handler data into invoker together with handler_fn.
Also it may be good idea to create a special invoker type for getAll,
since getAll invokers doesn't use handler_fn paramater at all.
Is it worth a ticket?
I am sending a new patch since I broke getAll calls.
>
> switch(ret) {
> @@ -313,6 +315,11 @@ int sbus_request_fail_and_finish(struct sbus_request *dbus_req,
> DBusMessage *reply;
> int ret;
>
> + if (error == NULL) {
> + sbus_request_finish(dbus_req, NULL);
> + return ENOMEM;
> + }
> +
> reply = dbus_message_new_error(dbus_req->message, error->name,
error->message);
> if (!reply) {
> DEBUG(SSSDBG_CRIT_FAILURE, "Out of memory allocating DBus
message\n");
LS
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