From: Al Viro <viro@zeniv.linux.org.uk>
Date: Fri, 20 Jul 2012 08:03:41 +0000 (+0400)
Subject: sanitize ecryptfs_lookup()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=bc65a1215eda3e067801e0a8f3eeffb62800f355;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

sanitize ecryptfs_lookup()

* ->lookup() never gets hit with . or ..
* dentry it gets is unhashed, so unless we had gone and hashed it ourselves, there's
no need to d_drop() the sucker.
* wrong name printed in one of the printks (NULL, in fact)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index ffa2be57804d..eeb734aea5ba 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -381,12 +381,6 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
 	struct dentry *lower_dir_dentry, *lower_dentry;
 	int rc = 0;
 
-	if ((ecryptfs_dentry->d_name.len == 1
-	     && !strcmp(ecryptfs_dentry->d_name.name, "."))
-	    || (ecryptfs_dentry->d_name.len == 2
-		&& !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
-		goto out_d_drop;
-	}
 	lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
 	mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
 	lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
@@ -397,8 +391,8 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
 		rc = PTR_ERR(lower_dentry);
 		ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
 				"[%d] on lower_dentry = [%s]\n", __func__, rc,
-				encrypted_and_encoded_name);
-		goto out_d_drop;
+				ecryptfs_dentry->d_name.name);
+		goto out;
 	}
 	if (lower_dentry->d_inode)
 		goto interpose;
@@ -415,7 +409,7 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
 	if (rc) {
 		printk(KERN_ERR "%s: Error attempting to encrypt and encode "
 		       "filename; rc = [%d]\n", __func__, rc);
-		goto out_d_drop;
+		goto out;
 	}
 	mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
 	lower_dentry = lookup_one_len(encrypted_and_encoded_name,
@@ -427,14 +421,11 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
 		ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
 				"[%d] on lower_dentry = [%s]\n", __func__, rc,
 				encrypted_and_encoded_name);
-		goto out_d_drop;
+		goto out;
 	}
 interpose:
 	rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry,
 				       ecryptfs_dir_inode);
-	goto out;
-out_d_drop:
-	d_drop(ecryptfs_dentry);
 out:
 	kfree(encrypted_and_encoded_name);
 	return ERR_PTR(rc);