From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
commit 6f0307df83f2aa6bdf656c2219c89ce96502d20e upstream.
When errors happens while loading graph components, the kernel oopses
while trying to remove all topology components. This can be
root-caused to a list pointing to memory that was already freed on
error.
remove_route() is already called on errors and will perform the
required cleanups so there's no need to free the route memory in
soc_tplg_dapm_graph_elems_load() if the route was added to the
list. We do however want to free the routes allocated but not added to
the list.
Fixes: 7df04ea7a31ea ('ASoC: topology: modify dapm route loading routine and add dapm route unloading')
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@xxxxxxxxxxxxxxx>
Reviewed-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200707203749.113883-2-pierre-louis.bossart@xxxxxxxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/soc/soc-topology.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)
--- a/sound/soc/soc-topology.c
+++ b/sound/soc/soc-topology.c
@@ -1284,17 +1284,29 @@ static int soc_tplg_dapm_graph_elems_loa
list_add(&routes[i]->dobj.list, &tplg->comp->dobj_list);
ret = soc_tplg_add_route(tplg, routes[i]);
- if (ret < 0)
+ if (ret < 0) {
+ /*
+ * this route was added to the list, it will
+ * be freed in remove_route() so increment the
+ * counter to skip it in the error handling
+ * below.
+ */
+ i++;
break;
+ }
/* add route, but keep going if some fail */
snd_soc_dapm_add_routes(dapm, routes[i], 1);
}
- /* free memory allocated for all dapm routes in case of error */
- if (ret < 0)
- for (i = 0; i < count ; i++)
- kfree(routes[i]);
+ /*
+ * free memory allocated for all dapm routes not added to the
+ * list in case of error
+ */
+ if (ret < 0) {
+ while (i < count)
+ kfree(routes[i++]);
+ }
/*
* free pointer to array of dapm routes as this is no longer needed.
