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From: "Peng Fan (OSS)" <peng.fan@oss.nxp.com>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	 Daniel Scally <djrscally@gmail.com>,
	 Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	 Sakari Ailus <sakari.ailus@linux.intel.com>,
	 Bartosz Golaszewski <brgl@kernel.org>,
	 Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	 "Rafael J. Wysocki" <rafael@kernel.org>,
	Danilo Krummrich <dakr@kernel.org>,
	 Johan Hovold <johan@kernel.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
	 linux-acpi@vger.kernel.org, driver-core@lists.linux.dev,
	 linux-kernel@vger.kernel.org, imx@lists.linux.dev,
	 Peng Fan <peng.fan@nxp.com>
Subject: [PATCH 2/4] software node: use kobject_get_unless_zero() in software_node_find_by_name()
Date: Wed, 04 Nov 2026 23:43:14 +0800	[thread overview]
Message-ID: <20261104-swnode-race-v1-v1-2-9406a67e25be@nxp.com> (raw)
In-Reply-To: <20261104-swnode-race-v1-v1-0-9406a67e25be@nxp.com>

From: Peng Fan <peng.fan@nxp.com>

software_node_find_by_name() also walks the swnode kset list and takes a
reference with swnode_get(). Like the pointer-based lookup, it can
encounter an entry whose refcount has already reached zero but which is
still linked until its delayed release callback runs.

Use kobject_get_unless_zero() and continue scanning when the entry is
already dying.

Fixes: 80488a6b1d3c ("software node: Add support for static node descriptors")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/base/swnode.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 19a4153f3fac1..9095d50ba146f 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -831,8 +831,8 @@ software_node_find_by_name(const struct software_node *parent, const char *name)
 		swnode = kobj_to_swnode(k);
 		if (parent == swnode->node->parent && swnode->node->name &&
 		    !strcmp(name, swnode->node->name)) {
-			swnode_get(swnode);
-			break;
+			if (kobject_get_unless_zero(k))
+				break;
 		}
 		swnode = NULL;
 	}

-- 
2.34.1


  parent reply	other threads:[~2026-11-04 15:38 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-04 15:43 [PATCH 0/4] software node: fix lookup of swnode in release path Peng Fan (OSS)
2026-11-04 15:43 ` [PATCH 1/4] software node: do not resurrect swnode being released Peng Fan (OSS)
2026-11-04 15:43 ` Peng Fan (OSS) [this message]
2026-11-04 21:29   ` [PATCH 2/4] software node: use kobject_get_unless_zero() in software_node_find_by_name() Andy Shevchenko
2026-11-04 15:43 ` [PATCH 3/4] software node: handle missing remote endpoint node Peng Fan (OSS)
2026-11-04 15:43 ` [PATCH 4/4] software node: skip dying children during traversal Peng Fan (OSS)

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