[PATCH 4.8 41/96] stm class: Fix device leak in open error path

From: Greg Kroah-Hartman
Date: Fri Jan 06 2017 - 16:53:54 EST


4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit a0ebf519b8a2666438d999c62995618c710573e5 upstream.

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

Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for...")
Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/hwtracing/stm/core.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -361,7 +361,7 @@ static int stm_char_open(struct inode *i
struct stm_file *stmf;
struct device *dev;
unsigned int major = imajor(inode);
- int err = -ENODEV;
+ int err = -ENOMEM;

dev = class_find_device(&stm_class, NULL, &major, major_match);
if (!dev)
@@ -369,8 +369,9 @@ static int stm_char_open(struct inode *i

stmf = kzalloc(sizeof(*stmf), GFP_KERNEL);
if (!stmf)
- return -ENOMEM;
+ goto err_put_device;

+ err = -ENODEV;
stm_output_init(&stmf->output);
stmf->stm = to_stm_device(dev);

@@ -382,9 +383,10 @@ static int stm_char_open(struct inode *i
return nonseekable_open(inode, file);

err_free:
+ kfree(stmf);
+err_put_device:
/* matches class_find_device() above */
put_device(dev);
- kfree(stmf);

return err;
}