From: Stephen Smalley <sds@tycho.nsa.gov>
Date: Wed, 21 Nov 2007 14:01:36 +0000 (-0500)
Subject: SELinux: do not clear f_op when removing entries
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=0955dc03aedfb6a5565445b3f2176255b784cc6a;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

SELinux: do not clear f_op when removing entries

Do not clear f_op when removing entries since it isn't safe to do.

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
---

diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index f5f3e6da5da7..ac6fe99bd32c 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -838,10 +838,6 @@ static ssize_t sel_read_bool(struct file *filep, char __user *buf,
 
 	ret = -EFAULT;
 
-	/* check to see if this file has been deleted */
-	if (!filep->f_op)
-		goto out;
-
 	if (count > PAGE_SIZE) {
 		ret = -EINVAL;
 		goto out;
@@ -882,10 +878,6 @@ static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
 	if (length)
 		goto out;
 
-	/* check to see if this file has been deleted */
-	if (!filep->f_op)
-		goto out;
-
 	if (count >= PAGE_SIZE) {
 		length = -ENOMEM;
 		goto out;
@@ -940,10 +932,6 @@ static ssize_t sel_commit_bools_write(struct file *filep,
 	if (length)
 		goto out;
 
-	/* check to see if this file has been deleted */
-	if (!filep->f_op)
-		goto out;
-
 	if (count >= PAGE_SIZE) {
 		length = -ENOMEM;
 		goto out;
@@ -982,11 +970,9 @@ static const struct file_operations sel_commit_bools_ops = {
 	.write          = sel_commit_bools_write,
 };
 
-/* partial revoke() from fs/proc/generic.c proc_kill_inodes */
 static void sel_remove_entries(struct dentry *de)
 {
-	struct list_head *p, *node;
-	struct super_block *sb = de->d_sb;
+	struct list_head *node;
 
 	spin_lock(&dcache_lock);
 	node = de->d_subdirs.next;
@@ -1006,18 +992,6 @@ static void sel_remove_entries(struct dentry *de)
 	}
 
 	spin_unlock(&dcache_lock);
-
-	file_list_lock();
-	list_for_each(p, &sb->s_files) {
-		struct file * filp = list_entry(p, struct file, f_u.fu_list);
-		struct dentry * dentry = filp->f_path.dentry;
-
-		if (dentry->d_parent != de) {
-			continue;
-		}
-		filp->f_op = NULL;
-	}
-	file_list_unlock();
 }
 
 #define BOOL_DIR_NAME "booleans"