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@linux.intel.com --- 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)