Make sure to drop the reference taken when looking up the th device during output device open() on errors and on close().

Note that a recent commit fixed the leak in a couple of open() error paths but not all of them, and the reference is still leaking on successful open().

Fixes: 39f4034693b7 ("intel_th: Add driver infrastructure for Intel(R) Trace Hub devices") Fixes: 6d5925b667e4 ("intel_th: Fix error handling in intel_th_output_open") Cc: stable@vger.kernel.org # 4.4: 6d5925b667e4 Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Ma Ke make24@iscas.ac.cn Signed-off-by: Johan Hovold johan@kernel.org --- drivers/hwtracing/intel_th/core.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c index 591b7c12aae5..d9c17214d3dc 100644 --- a/drivers/hwtracing/intel_th/core.c +++ b/drivers/hwtracing/intel_th/core.c @@ -810,9 +810,12 @@ static int intel_th_output_open(struct inode *inode, struct file *file) int err;

dev = bus_find_device_by_devt(&intel_th_bus, inode->i_rdev); - if (!dev || !dev->driver) { + if (!dev) + return -ENODEV; + + if (!dev->driver) { err = -ENODEV; - goto out_no_device; + goto out_put_device; }

thdrv = to_intel_th_driver(dev->driver); @@ -836,12 +839,22 @@ static int intel_th_output_open(struct inode *inode, struct file *file)

out_put_device: put_device(dev); -out_no_device: + return err; }

+static int intel_th_output_release(struct inode *inode, struct file *file) +{ + struct intel_th_device *thdev = file->private_data; + + put_device(&thdev->dev); + + return 0; +} + static const struct file_operations intel_th_output_fops = { .open = intel_th_output_open, + .release = intel_th_output_release, .llseek = noop_llseek, };