From 61b5865d56bbb09dd5887b197dd324d1d4333d47 Mon Sep 17 00:00:00 2001
From: Dave Jiang <dave.jiang@intel.com>
Date: Tue, 11 Feb 2020 10:42:47 -0700
Subject: [PATCH] dmaengine: idxd: fix runaway module ref count on device driver bind
Git-commit: 61b5865d56bbb09dd5887b197dd324d1d4333d47
Patch-mainline: v5.6-rc5
References: jsc#SLE-12688

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/dma/idxd/sysfs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 6d907fe150aa..298855ca934f 100644
--- 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;
 		}
-- 
2.16.4