From 017f8da43e92ddd9989884720b694a512e09ccce Mon Sep 17 00:00:00 2001 From: Hin-Tak Leung Date: Fri, 6 Jun 2014 14:36:21 -0700 Subject: hfsplus: fix worst-case unicode to char conversion of file names and attributes This is a series of 3 patches which corrects issues in HFS+ concerning the use of non-english file names and attributes. Names and attributes are stored internally as UTF-16 units up to a fixed maximum size, and convert to and from user-representation by NLS. The code incorrectly assume that NLS string lengths are equal to unicode lengths, which is only true for English ascii usage. This patch (of 3): The HFS Plus Volume Format specification (TN1150) states that file names are stored internally as a maximum of 255 unicode characters, as defined by The Unicode Standard, Version 2.0 [Unicode, Inc. ISBN 0-201-48345-9]. File names are converted by the NLS system on Linux before presented to the user. 255 CJK characters converts to UTF-8 with 1 unicode character to up to 3 bytes, and to GB18030 with 1 unicode character to up to 4 bytes. Thus, trying in a UTF-8 locale to list files with names of more than 85 CJK characters results in: $ ls /mnt ls: reading directory /mnt: File name too long The receiving buffer to hfsplus_uni2asc() needs to be 255 x NLS_MAX_CHARSET_SIZE bytes, not 255 bytes as the code has always been. Similar consideration applies to attributes, which are stored internally as a maximum of 127 UTF-16BE units. See XNU source for an up-to-date reference on attributes. Strictly speaking, the maximum value of NLS_MAX_CHARSET_SIZE = 6 is not attainable in the case of conversion to UTF-8, as going beyond 3 bytes requires the use of surrogate pairs, i.e. consuming two input units. Thanks Anton Altaparmakov for reviewing an earlier version of this change. This patch fixes all callers of hfsplus_uni2asc(), and also enables the use of long non-English file names in HFS+. The getting and setting, and general usage of long non-English attributes requires further forthcoming work, in the following patches of this series. [akpm@linux-foundation.org: fix build] Signed-off-by: Hin-Tak Leung Reviewed-by: Anton Altaparmakov Cc: Vyacheslav Dubeyko Cc: Al Viro Cc: Christoph Hellwig Cc: Sougata Santra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/hfsplus/xattr.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'fs/hfsplus/xattr.c') diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c index 4e27edc082a4..e2b3c9ea1c71 100644 --- a/fs/hfsplus/xattr.c +++ b/fs/hfsplus/xattr.c @@ -8,6 +8,7 @@ #include "hfsplus_fs.h" #include +#include #include "xattr.h" #include "acl.h" @@ -645,8 +646,7 @@ ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size) struct hfs_find_data fd; u16 key_len = 0; struct hfsplus_attr_key attr_key; - char strbuf[HFSPLUS_ATTR_MAX_STRLEN + - XATTR_MAC_OSX_PREFIX_LEN + 1] = {0}; + char *strbuf; int xattr_name_len; if ((!S_ISREG(inode->i_mode) && @@ -666,6 +666,13 @@ ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size) return err; } + strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + + XATTR_MAC_OSX_PREFIX_LEN + 1, GFP_KERNEL); + if (!strbuf) { + res = -ENOMEM; + goto out; + } + err = hfsplus_find_attr(inode->i_sb, inode->i_ino, NULL, &fd); if (err) { if (err == -ENOENT) { @@ -692,7 +699,7 @@ ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size) if (be32_to_cpu(attr_key.cnid) != inode->i_ino) goto end_listxattr; - xattr_name_len = HFSPLUS_ATTR_MAX_STRLEN; + xattr_name_len = NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN; if (hfsplus_uni2asc(inode->i_sb, (const struct hfsplus_unistr *)&fd.key->attr.key_name, strbuf, &xattr_name_len)) { @@ -718,6 +725,8 @@ ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size) } end_listxattr: + kfree(strbuf); +out: hfs_find_exit(&fd); return res; } -- cgit v1.2.3