Re: [PATCH v3 1/4] qemu-ga: 'Null' check for mandatory parameters

[Konstantin Kostiuk <kkostiuk@redhat.com>]

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On Mon, Oct 21, 2024 at 7:45 PM Daniel P. Berrangé <berrange@redhat.com>
wrote:

> On Mon, Oct 21, 2024 at 09:28:36PM +0800, Dehan Meng wrote:
> > sscanf return values are checked and add 'Null' check for
> > mandatory parameters.
> >
> > Signed-off-by: Dehan Meng <demeng@redhat.com>
> > ---
> >  qga/commands-linux.c | 12 +++++++++++-
> >  1 file changed, 11 insertions(+), 1 deletion(-)
> >
> > diff --git a/qga/commands-linux.c b/qga/commands-linux.c
> > index 51d5e3d927..f0e9cdd27c 100644
> > --- a/qga/commands-linux.c
> > +++ b/qga/commands-linux.c
> > @@ -2103,7 +2103,9 @@ static char *hexToIPAddress(const void *hexValue,
> int is_ipv6)
> >          int i;
> >
> >          for (i = 0; i < 16; i++) {
> > -            sscanf(&hexStr[i * 2], "%02hhx", &in6.s6_addr[i]);
> > +            if (sscanf(&hex_str[i * 2], "%02hhx", &in6.s6_addr[i]) !=
> 1) {
> > +                return NULL;
> > +            }
> >          }
> >          inet_ntop(AF_INET6, &in6, addr, INET6_ADDRSTRLEN);
> >
> > @@ -2164,6 +2166,10 @@ GuestNetworkRouteList
> *qmp_guest_network_get_route(Error **errp)
> >                  networkroute = route;
> >                  networkroute->iface = g_strdup(Iface);
> >                  networkroute->destination = hexToIPAddress(Destination,
> 1);
> > +                if (networkroute->destination == NULL) {
> > +                    g_free(route);
> > +                    continue;
> > +                }
>
> This is still leaking the 'networkroute->iface' string.
>
> The existing code is a bit strange having 'route' and 'networkroute'
> variables.
>
> I'd suggest removing the "route" variable entirely.
>

This part was done in patch 4/4


>
> Then have a code pattern that relies on g_autoptr to automatically
> free the struct & all its fields.
>

Agree with this


>
> eg something that looks approx like this:
>
>    g_autoptr(GuestNetorkRoute) networkroute = NULL;
>
>    ...
>
>    if (is_ipv6) {
>        ...
>        networkroute = g_new0(GuestNetorkRoute, 1);
>        networkroute->iface = g_strdup(Iface);
>        networkroute->destination = hexToIPAddress(Destination, 1);
>        if (networkroute->destination == NULL) {
>           continue;
>        }
>        ...
>    } else {
>        ...
>        networkroute = g_new0(GuestNetorkRoute, 1);
>        networkroute->iface = g_strdup(Iface);
>        networkroute->destination = hexToIPAddress(Destination, 1);
>        if (networkroute->destination == NULL) {
>           continue;
>        }
>        ...
>    }
>
>    QAPI_LIST_APPEND(tail, g_steal_pointer(&networkroute));
>
>
> >                  networkroute->metric = Metric;
> >                  networkroute->source = hexToIPAddress(Source, 1);
> >                  networkroute->desprefixlen = g_strdup_printf(
> > @@ -2195,6 +2201,10 @@ GuestNetworkRouteList
> *qmp_guest_network_get_route(Error **errp)
> >                  networkroute = route;
> >                  networkroute->iface = g_strdup(Iface);
> >                  networkroute->destination =
> hexToIPAddress(&Destination, 0);
> > +                if (networkroute->destination == NULL) {
> > +                    g_free(route);
> > +                    continue;
> > +                }
> >                  networkroute->gateway = hexToIPAddress(&Gateway, 0);
> >                  networkroute->mask = hexToIPAddress(&Mask, 0);
> >                  networkroute->metric = Metric;
> > --
> > 2.40.1
> >
>
> With regards,
> Daniel
> --
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>

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