linux-kernel - [PATCH v2] phy: Fix error handling in tegra_xusb_pad

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-next>] [day] [month] [year] [list]

Message-Id: <20251104012820.35336-1-make24@iscas.ac.cn>
Date: Tue,  4 Nov 2025 09:28:20 +0800
From: Ma Ke <make24@...as.ac.cn>
To: jckuo@...dia.com,
	vkoul@...nel.org,
	kishon@...nel.org,
	thierry.reding@...il.com,
	jonathanh@...dia.com
Cc: linux-phy@...ts.infradead.org,
	linux-tegra@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	akpm@...ux-foundation.org,
	Ma Ke <make24@...as.ac.cn>,
	stable@...r.kernel.org
Subject: [PATCH v2] phy: Fix error handling in tegra_xusb_pad_init

If device_add() fails, do not use device_unregister() for error
handling. device_unregister() consists two functions: device_del() and
put_device(). device_unregister() should only be called after
device_add() succeeded because device_del() undoes what device_add()
does if successful.

As comment of device_add() says, 'if device_add() succeeds, you should
call device_del() when you want to get rid of it. If device_add() has
not succeeded, use only put_device() to drop the reference count'.

In tegra_xusb_pad_init(), both dev_set_name() and device_add() may
fail. In either case, we should only use put_device(). After
device_initialize(), the device has a reference count of 1. If
dev_set_name() fails, device_add() has not been called. If
device_add() fails, it has already cleaned up after itself.
device_unregister() would incorrectly call device_del() when
device_add() was never successful. Therefore, change both error paths
to use put_device() instead of device_unregister().

Found by code review.

Cc: stable@...r.kernel.org
Fixes: 53d2a715c240 ("phy: Add Tegra XUSB pad controller support")
Signed-off-by: Ma Ke <make24@...as.ac.cn>
---
Changes in v2:
- modified the Fixes tag;
- modified the patch description.
---
 drivers/phy/tegra/xusb.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c
index c89df95aa6ca..d89493d68699 100644
--- a/drivers/phy/tegra/xusb.c
+++ b/drivers/phy/tegra/xusb.c
@@ -171,16 +171,16 @@ int tegra_xusb_pad_init(struct tegra_xusb_pad *pad,

 	err = dev_set_name(&pad->dev, "%s", pad->soc->name);
 	if (err < 0)
-		goto unregister;
+		goto put_device;

 	err = device_add(&pad->dev);
 	if (err < 0)
-		goto unregister;
+		goto put_device;

 	return 0;

-unregister:
-	device_unregister(&pad->dev);
+put_device:
+	put_device(&pad->dev);
 	return err;
 }

-- 
2.17.1