linux-kernel - [PATCH v3 1/2] intel_th: fix device leak on output open()

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20251208153524.68637-2-johan@kernel.org>
Date: Mon,  8 Dec 2025 16:35:23 +0100
From: Johan Hovold <johan@...nel.org>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>
Cc: linux-kernel@...r.kernel.org,
	Johan Hovold <johan@...nel.org>,
	stable@...r.kernel.org,
	Ma Ke <make24@...as.ac.cn>
Subject: [PATCH v3 1/2] intel_th: fix device leak on output open()

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@...r.kernel.org	# 4.4: 6d5925b667e4
Cc: Alexander Shishkin <alexander.shishkin@...ux.intel.com>
Cc: Ma Ke <make24@...as.ac.cn>
Signed-off-by: Johan Hovold <johan@...nel.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,
 };
 
-- 
2.52.0