1 files changed, 29 insertions, 8 deletions

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 55b3145b8072..93bc0f8174a7 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -379,9 +379,11 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
                 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,
                                       lower_dir_dentry,
                                       ecryptfs_dentry->d_name.len);
+        mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
         if (IS_ERR(lower_dentry)) {
                 rc = PTR_ERR(lower_dentry);
                 printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
@@ -406,9 +408,11 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
                        "filename; rc = [%d]\n", __func__, rc);
                 goto out_d_drop;
         }
+        mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
         lower_dentry = lookup_one_len(encrypted_and_encoded_name,
                                       lower_dir_dentry,
                                       encrypted_and_encoded_name_size - 1);
+        mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
         if (IS_ERR(lower_dentry)) {
                 rc = PTR_ERR(lower_dentry);
                 printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
@@ -636,8 +640,9 @@ static int
 ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
 {
         char *lower_buf;
+        size_t lower_bufsiz;
         struct dentry *lower_dentry;
-        struct ecryptfs_crypt_stat *crypt_stat;
+        struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
         char *plaintext_name;
         size_t plaintext_name_size;
         mm_segment_t old_fs;
@@ -648,12 +653,21 @@ ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
                 rc = -EINVAL;
                 goto out;
         }
-        crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
+        mount_crypt_stat = &ecryptfs_superblock_to_private(
+                                                dentry->d_sb)->mount_crypt_stat;
+        /*
+         * If the lower filename is encrypted, it will result in a significantly
+         * longer name.  If needed, truncate the name after decode and decrypt.
+         */
+        if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
+                lower_bufsiz = PATH_MAX;
+        else
+                lower_bufsiz = bufsiz;
         /* Released in this function */
-        lower_buf = kmalloc(bufsiz, GFP_KERNEL);
+        lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
         if (lower_buf == NULL) {
                 printk(KERN_ERR "%s: Out of memory whilst attempting to "
-                       "kmalloc [%d] bytes\n", __func__, bufsiz);
+                       "kmalloc [%d] bytes\n", __func__, lower_bufsiz);
                 rc = -ENOMEM;
                 goto out;
         }
@@ -661,7 +675,7 @@ ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
         set_fs(get_ds());
         rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
                                                    (char __user *)lower_buf,
-                                                   bufsiz);
+                                                   lower_bufsiz);
         set_fs(old_fs);
         if (rc >= 0) {
                 rc = ecryptfs_decode_and_decrypt_filename(&plaintext_name,
@@ -674,7 +688,9 @@ ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
                                 rc);
                         goto out_free_lower_buf;
                 }
-                rc = copy_to_user(buf, plaintext_name, plaintext_name_size);
+                /* Check for bufsiz <= 0 done in sys_readlinkat() */
+                rc = copy_to_user(buf, plaintext_name,
+                                  min((unsigned) bufsiz, plaintext_name_size));
                 if (rc)
                         rc = -EFAULT;
                 else
@@ -814,6 +830,13 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
                 size_t num_zeros = (PAGE_CACHE_SIZE
                                     - (new_length & ~PAGE_CACHE_MASK));
 
+                if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
+                        rc = vmtruncate(inode, new_length);
+                        if (rc)
+                                goto out_free;
+                        rc = vmtruncate(lower_dentry->d_inode, new_length);
+                        goto out_free;
+                }
                 if (num_zeros) {
                         char *zeros_virt;
 
@@ -915,8 +938,6 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
                         }
                         rc = 0;
                         crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
-                        mutex_unlock(&crypt_stat->cs_mutex);
-                        goto out;
                 }
         }
         mutex_unlock(&crypt_stat->cs_mutex);