[PATCH] securityfs: fix missing of d_delete() in securityfs_remove()

From: alexjlzheng
Date: Fri Apr 25 2025 - 05:26:27 EST


From: Jinliang Zheng <alexjlzheng@xxxxxxxxxxx>

Consider the following module code:

static struct dentry *dentry;

static int __init securityfs_test_init(void)
{
dentry = securityfs_create_dir("standon", NULL);
return PTR_ERR(dentry);
}

static void __exit securityfs_test_exit(void)
{
securityfs_remove(dentry);
}

module_init(securityfs_test_init);
module_exit(securityfs_test_exit);

and then:

insmod /path/to/thismodule
cd /sys/kernel/security/standon <- we hold 'standon'
rmmod thismodule <- 'standon' don't go away
insmod /path/to/thismodule <- Failed: File exists!

Fix this by adding d_delete() in securityfs_remove().

Fixes: b67dbf9d4c198 ("[PATCH] add securityfs for all LSMs to use")
Signed-off-by: Jinliang Zheng <alexjlzheng@xxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
security/inode.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/security/inode.c b/security/inode.c
index da3ab44c8e57..d99baf26350a 100644
--- a/security/inode.c
+++ b/security/inode.c
@@ -306,6 +306,7 @@ void securityfs_remove(struct dentry *dentry)
simple_rmdir(dir, dentry);
else
simple_unlink(dir, dentry);
+ d_delete(dentry);
dput(dentry);
}
inode_unlock(dir);
--
2.49.0