[PATCH] stm class: fix device leak in open error path

[Johan Hovold <johan@kernel.org>]

Make sure to drop the reference taken by class_find_device() also on
allocation errors in open().

Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for...")
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/hwtracing/stm/core.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index 51f81d64ca37..47811f5c9bc9 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -368,8 +368,10 @@ static int stm_char_open(struct inode *inode, struct file *file)
 		return -ENODEV;
 
 	stmf = kzalloc(sizeof(*stmf), GFP_KERNEL);
-	if (!stmf)
-		return -ENOMEM;
+	if (!stmf) {
+		err = -ENOMEM;
+		goto err_put_device;
+	}
 
 	stm_output_init(&stmf->output);
 	stmf->stm = to_stm_device(dev);
@@ -382,9 +384,10 @@ static int stm_char_open(struct inode *inode, struct file *file)
 	return nonseekable_open(inode, file);
 
 err_free:
+	kfree(stmf);
+err_put_device:
 	/* matches class_find_device() above */
 	put_device(dev);
-	kfree(stmf);
 
 	return err;
 }
-- 
2.7.3