Patch "driver core: Fix error handling in driver API device_rename()" has been added to the 6.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    driver core: Fix error handling in driver API device_rename()

to the 6.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     driver-core-fix-error-handling-in-driver-api-device_.patch
and it can be found in the queue-6.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 7a93c33564429ab55ac9b3a6ed803e3b71d81eca
Author: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
Date:   Mon Jul 22 22:48:10 2024 +0800

    driver core: Fix error handling in driver API device_rename()
    
    [ Upstream commit 6d8249ac29bc23260dfa9747eb398ce76012d73c ]
    
    For class-device, device_rename() failure maybe cause unexpected link name
    within its class folder as explained below:
    
    /sys/class/.../old_name -> /sys/devices/.../old_name
    device_rename(..., new_name) and failed
    /sys/class/.../new_name -> /sys/devices/.../old_name
    
    Fixed by undoing renaming link if renaming kobject failed.
    
    Fixes: f349cf34731c ("driver core: Implement ns directory support for device classes.")
    Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240722-device_rename_fix-v2-1-77de1a6c6495@xxxxxxxxxxx
    Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/base/core.c b/drivers/base/core.c
index b5399262198a6..6c1a944c00d9b 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4515,9 +4515,11 @@ EXPORT_SYMBOL_GPL(device_destroy);
  */
 int device_rename(struct device *dev, const char *new_name)
 {
+	struct subsys_private *sp = NULL;
 	struct kobject *kobj = &dev->kobj;
 	char *old_device_name = NULL;
 	int error;
+	bool is_link_renamed = false;
 
 	dev = get_device(dev);
 	if (!dev)
@@ -4532,7 +4534,7 @@ int device_rename(struct device *dev, const char *new_name)
 	}
 
 	if (dev->class) {
-		struct subsys_private *sp = class_to_subsys(dev->class);
+		sp = class_to_subsys(dev->class);
 
 		if (!sp) {
 			error = -EINVAL;
@@ -4541,16 +4543,19 @@ int device_rename(struct device *dev, const char *new_name)
 
 		error = sysfs_rename_link_ns(&sp->subsys.kobj, kobj, old_device_name,
 					     new_name, kobject_namespace(kobj));
-		subsys_put(sp);
 		if (error)
 			goto out;
+
+		is_link_renamed = true;
 	}
 
 	error = kobject_rename(kobj, new_name);
-	if (error)
-		goto out;
-
 out:
+	if (error && is_link_renamed)
+		sysfs_rename_link_ns(&sp->subsys.kobj, kobj, new_name,
+				     old_device_name, kobject_namespace(kobj));
+	subsys_put(sp);
+
 	put_device(dev);
 
 	kfree(old_device_name);