regmap: cache: bail in regmap_async_complete() for bus-less maps

commit f2e055e7c9c6084bfbaa68701e52562acf96419e upstream.

Commit f8bd822cb ("regmap: cache: Factor out block sync") made
regcache_rbtree_sync() call regmap_async_complete(), which in turn does
not check for map->bus before dereferencing it.

This causes a NULL pointer dereference on bus-less maps.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index a941dcfe7590..d0c81d1f409c 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1717,7 +1717,7 @@ int regmap_async_complete(struct regmap *map)
         int ret;
 
         /* Nothing to do with no async support */
-        if (!map->bus->async_write)
+        if (!map->bus || !map->bus->async_write)
                 return 0;
 
         trace_regmap_async_complete_start(map->dev);