[PATCH] intel_th: fix device leak on output open()

Johan Hovold
2025-11-21T10:51:16Z

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

Fixes: 39f4034693b7 ("intel_th: Add driver infrastructure for Intel(R) Trace Hub devices")
Cc: stable@vger.kernel.org # 4.4
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/hwtracing/intel_th/core.c | 28 +++++++++++++++++++++++++---
1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c
index 47d9e6c3bac0..ddc51de2d775 100644
--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -810,13 +810,20 @@ 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 err_put_dev;
+ }
+
thdrv = to_intel_th_driver(dev->driver);
fops = fops_get(thdrv->fops);
- if (!fops)
- return -ENODEV;
+ if (!fops) {
+ err = -ENODEV;
+ goto err_put_dev;
+ }

replace_fops(file, fops);

@@ -827,11 +834,26 @@ static int intel_th_output_open(struct inode *inode, struct file *file)
return err;
}

+ return 0;
+
+err_put_dev:
+ put_device(dev);
+
+ 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,
};

--
2.51.2