xen-block: stop leaking memory in xen_block_drive_create()

The locally allocated QDict-s need to be freed. ('file_layer' will be
freed implicitly since it is added as an object to 'driver_layer').

Spotted by Coverity: CID 1398649

While in the neighbourhood free 'driver' and 'filename' as soon as they are
added to the QDicts. Freeing after the 'done' label doesn't make that much
sense as, if the error path jumps to that label, the values would be NULL
anyway.

This patch also makes that more obvious by taking the error path if
'params' is NULL and then asserting that both driver and filename are
non-NULL in the normal path.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Message-Id: <20190219163440.15702-1-paul.durrant@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This commit is contained in:
Paul Durrant 2019-02-19 16:34:40 +00:00 committed by Anthony PERARD
parent 2ae23f0ecf
commit 156ac94463

View File

@ -743,12 +743,12 @@ static XenBlockDrive *xen_block_drive_create(const char *id,
}
g_strfreev(v);
}
if (!filename) {
error_setg(errp, "no filename");
} else {
error_setg(errp, "no params");
goto done;
}
assert(filename);
assert(driver);
drive = g_new0(XenBlockDrive, 1);
@ -758,6 +758,7 @@ static XenBlockDrive *xen_block_drive_create(const char *id,
qdict_put_str(file_layer, "driver", "file");
qdict_put_str(file_layer, "filename", filename);
g_free(filename);
if (mode && *mode != 'w') {
qdict_put_bool(file_layer, "read-only", true);
@ -793,16 +794,17 @@ static XenBlockDrive *xen_block_drive_create(const char *id,
driver_layer = qdict_new();
qdict_put_str(driver_layer, "driver", driver);
g_free(driver);
qdict_put_obj(driver_layer, "file", QOBJECT(file_layer));
g_assert(!drive->node_name);
drive->node_name = xen_block_blockdev_add(drive->id, driver_layer,
&local_err);
done:
g_free(driver);
g_free(filename);
qobject_unref(driver_layer);
done:
if (local_err) {
error_propagate(errp, local_err);
xen_block_drive_destroy(drive, NULL);