On Thu, Nov 21, 2019 at 09:58:30AM +0100, Erik Skultety wrote:
After libvirt switched to GLib, we also started to use glib allocation primitives as of commit e85e34f3. Unlike malloc which is ambiguous with regards to size == 0 (which in our case returned a unique pointer safe to be passed to free), g_malloc0 strictly returns NULL on size == 0.
This change broke our legacy APIs which rely on the caller to pre-allocate the target buffer to hold the results and pass the buffer size as an argument. Since it makes very little sense to call an API with nowhere to store the results, fix this by returning 0 directly in such case in the RPC dispatch code - there are modern API equivalents allocating the target buffer automatically anyway.
As mentioned before, I don't think we should be short-circuiting the driver APIs like this. It is still valid to call the APIs with zero length list such that we get access control checks validated.
https://bugzilla.redhat.com/show_bug.cgi?id=1772842
Signed-off-by: Erik Skultety <eskultet@redhat.com> --- src/rpc/gendispatch.pl | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/src/rpc/gendispatch.pl b/src/rpc/gendispatch.pl index 8656c8f205..524d31f741 100755 --- a/src/rpc/gendispatch.pl +++ b/src/rpc/gendispatch.pl @@ -1073,6 +1073,14 @@ elsif ($mode eq "server") { print " goto cleanup;\n"; print " }\n"; print "\n"; + + + print " if (args->$single_ret_list_max_var == 0) {\n"; + print " ret->$single_ret_list_name.${single_ret_list_name}_len = 0;\n"; + print " rv = 0;\n"; + print " goto cleanup;\n"; + print " }\n"; + print "\n"; }
print join("\n", @getters_list); -- 2.23.0
-- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|