From: Liu Ye <liuye@kylinos.cn>
Date: Wed, 5 Mar 2025 07:17:59 +0000 (+0800)
Subject: mm/shrinker: fix name consistency issue in shrinker_debugfs_rename()
X-Git-Tag: v6.15-rc1~81^2~169
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ac55b38fe2f9b486031439c5c4ed7fce07d0d838;p=thirdparty%2Flinux.git

mm/shrinker: fix name consistency issue in shrinker_debugfs_rename()

After calling debugfs_change_name function, the return value should be
checked and the old name restored.  If debugfs_change_name fails, the new
name memory should be freed.  The effect is that the shrinker->name is not
consistent with the name displayed in debugfs.

Link: https://lkml.kernel.org/r/20250305071759.661055-1-liuye@kylinos.cn
Signed-off-by: Liu Ye <liuye@kylinos.cn>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Reviewed-by：Qi Zheng <zhengqi.arch@bytedance.co
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c
index 794bd433cce0c..20eaee3e97f7a 100644
--- a/mm/shrinker_debug.c
+++ b/mm/shrinker_debug.c
@@ -214,10 +214,14 @@ int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...)
 	ret = debugfs_change_name(shrinker->debugfs_entry, "%s-%d",
 			shrinker->name, shrinker->debugfs_id);
 
+	if (ret) {
+		shrinker->name = old;
+		kfree_const(new);
+	} else {
+		kfree_const(old);
+	}
 	mutex_unlock(&shrinker_mutex);
 
-	kfree_const(old);
-
 	return ret;
 }
 EXPORT_SYMBOL(shrinker_debugfs_rename);