When the implementation only creates a sdw_master_device and does not
provide a master_name, we have a risk of kernel oopses with dereferences
of a NULL pointer.
Protect with explicit tests.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
---
drivers/soundwire/bus_type.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/drivers/soundwire/bus_type.c b/drivers/soundwire/bus_type.c
index 09a25075e770..c01d74c709d5 100644
--- a/drivers/soundwire/bus_type.c
+++ b/drivers/soundwire/bus_type.c
@@ -48,12 +48,14 @@ static int sdw_bus_match(struct device *dev, struct device_driver *ddrv)
md = dev_to_sdw_master_device(dev);
mdrv = drv_to_sdw_master_driver(ddrv);
- /*
- * we don't have any hardware information so
- * match with a hopefully unique string
- */
- ret = !strncmp(md->master_name, mdrv->driver.name,
- strlen(md->master_name));
+ if (md->master_name) {
+ /*
+ * we don't have any hardware information so
+ * match with a hopefully unique string
+ */
+ ret = !strncmp(md->master_name, mdrv->driver.name,
+ strlen(md->master_name));
+ }
}
return ret;
}
@@ -71,9 +73,11 @@ static int sdw_master_modalias(const struct sdw_master_device *md,
char *buf, size_t size)
{
/* modalias is sdw:<string> since we don't have any hardware info */
-
- return snprintf(buf, size, "sdw:%s\n",
- md->master_name);
+ if (md->master_name)
+ return snprintf(buf, size, "sdw:%s\n",
+ md->master_name);
+ else
+ return snprintf(buf, size, "sdw:no_master_driver\n");
}
static int sdw_uevent(struct device *dev, struct kobj_uevent_env *env)
--
2.20.1
