dmaengine: idxd: fix runaway module ref count on device driver bind

idxd_config_bus_probe() calls try_module_get() but never calls module_put()
when it fails. Thus with every failed attempt, the ref count goes up. Add
module_put() in failure paths.

Fixes: c52ca478233c ("dmaengine: idxd: add configuration component of driver")
Reported-by: Jerry Chen <jerry.t.chen@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/158144296730.41381.12134210685456322434.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 6d907fe..298855c 100644 (file)
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -124,6 +124,7 @@ static int idxd_config_bus_probe(struct device *dev)
                rc = idxd_device_config(idxd);
                if (rc < 0) {
                        spin_unlock_irqrestore(&idxd->dev_lock, flags);
+                       module_put(THIS_MODULE);
                        dev_warn(dev, "Device config failed: %d\n", rc);
                        return rc;
                }
@@ -132,6 +133,7 @@ static int idxd_config_bus_probe(struct device *dev)
                rc = idxd_device_enable(idxd);
                if (rc < 0) {
                        spin_unlock_irqrestore(&idxd->dev_lock, flags);
+                       module_put(THIS_MODULE);
                        dev_warn(dev, "Device enable failed: %d\n", rc);
                        return rc;
                }
@@ -142,6 +144,7 @@ static int idxd_config_bus_probe(struct device *dev)
                rc = idxd_register_dma_device(idxd);
                if (rc < 0) {
                        spin_unlock_irqrestore(&idxd->dev_lock, flags);
+                       module_put(THIS_MODULE);
                        dev_dbg(dev, "Failed to register dmaengine device\n");
                        return rc;
                }