hfsplus: fix worst-case unicode to char conversion of file names and attributes (017f8da4) · Commits · 戴 / test

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 <htl10@users.sourceforge.net> Reviewed-by:

Anton Altaparmakov <anton@tuxera.com> Cc: Vyacheslav Dubeyko <slava@dubeyko.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Sougata Santra <sougata@tuxera.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/hfsplus/dir.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -12,6 +12,7 @@
		#include <linux/fs.h>
		#include <linux/slab.h>
		#include <linux/random.h>
		#include <linux/nls.h>

		#include "hfsplus_fs.h"
		#include "hfsplus_raw.h"
		@@ -127,7 +128,7 @@ static int hfsplus_readdir(struct file file, struct dir_context ctx)
		struct inode *inode = file_inode(file);
		struct super_block *sb = inode->i_sb;
		int len, err;
		char strbuf[HFSPLUS_MAX_STRLEN + 1];
		char *strbuf;
		hfsplus_cat_entry entry;
		struct hfs_find_data fd;
		struct hfsplus_readdir_data *rd;
		@@ -139,6 +140,11 @@ static int hfsplus_readdir(struct file file, struct dir_context ctx)
		err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
		if (err)
		return err;
		strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
		if (!strbuf) {
		err = -ENOMEM;
		goto out;
		}
		hfsplus_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
		err = hfs_brec_find(&fd, hfs_find_rec_by_key);
		if (err)
		@@ -193,7 +199,7 @@ static int hfsplus_readdir(struct file file, struct dir_context ctx)
		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
		fd.entrylength);
		type = be16_to_cpu(entry.type);
		len = HFSPLUS_MAX_STRLEN;
		len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
		if (err)
		goto out;
		@@ -246,6 +252,7 @@ next:
		}
		memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
		out:
		kfree(strbuf);
		hfs_find_exit(&fd);
		return err;
		}

fs/hfsplus/xattr.c

+12 −3

Original line number	Diff line number	Diff line
		@@ -8,6 +8,7 @@

		#include "hfsplus_fs.h"
		#include <linux/posix_acl_xattr.h>
		#include <linux/nls.h>
		#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;
		}

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