diff options
| -rw-r--r-- | fs/ecryptfs/inode.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index d832526..93bc0f8 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -640,8 +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; @@ -652,12 +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; } @@ -665,7 +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, @@ -678,7 +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 |