[RFC PATCH 13/20] hfsplus: Do not use broken utf8 NLS table for iocharset=utf8 mount option
From: Pali Rohár <pali@kernel.org>
Date: 2021-08-08 16:25:43
Also in:
linux-fsdevel, lkml
Subsystem:
filesystems (vfs and infrastructure), hfsplus filesystem, the rest · Maintainers:
Alexander Viro, Christian Brauner, Viacheslav Dubeyko, John Paul Adrian Glaubitz, Yangtao Li, Linus Torvalds
NLS table for utf8 is broken and cannot be fixed. So instead of broken utf8 nls functions char2uni() and uni2char() use functions utf8_to_utf32() and utf32_to_utf8() which implements correct encoding and decoding between Unicode code points and UTF-8 sequence. Note that this fs driver does not support full Unicode range, specially UTF-16 surrogate pairs are unsupported. This patch does not change this limitation and support for UTF-16 surrogate pairs stay unimplemented. When iochatset=utf8 is used then set sbi->nls to NULL and use it for distinguish between the fact if NLS table or native UTF-8 functions should be used. Signed-off-by: Pali Rohár <pali@kernel.org> --- fs/hfsplus/dir.c | 6 ++++-- fs/hfsplus/options.c | 32 ++++++++++++++++++-------------- fs/hfsplus/super.c | 7 +------ fs/hfsplus/unicode.c | 31 ++++++++++++++++++++++++++++--- fs/hfsplus/xattr.c | 14 +++++++++----- fs/hfsplus/xattr_security.c | 3 ++- 6 files changed, 62 insertions(+), 31 deletions(-)
diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c
index 84714bbccc12..2caf0cd82221 100644
--- a/fs/hfsplus/dir.c
+++ b/fs/hfsplus/dir.c@@ -144,7 +144,8 @@ 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); + strbuf = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) * + HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL); if (!strbuf) { err = -ENOMEM; goto out;
@@ -203,7 +204,8 @@ 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 = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN; + len = (HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) * + HFSPLUS_MAX_STRLEN; err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len); if (err) goto out;
diff --git a/fs/hfsplus/options.c b/fs/hfsplus/options.c
index a975548f6b91..16c08cb5c4f8 100644
--- a/fs/hfsplus/options.c
+++ b/fs/hfsplus/options.c@@ -104,6 +104,9 @@ int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi) char *p; substring_t args[MAX_OPT_ARGS]; int tmp, token; + int have_iocharset; + + have_iocharset = 0; if (!input) goto done;
@@ -171,20 +174,24 @@ int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi) pr_warn("option nls= is deprecated, use iocharset=\n"); /* fallthrough */ case opt_iocharset: - if (sbi->nls) { + if (have_iocharset) { pr_err("unable to change nls mapping\n"); return 0; } p = match_strdup(&args[0]); - if (p) - sbi->nls = load_nls(p); - if (!sbi->nls) { - pr_err("unable to load nls mapping \"%s\"\n", - p); - kfree(p); + if (!p) return 0; + if (strcmp(p, "utf8") != 0) { + sbi->nls = load_nls(p); + if (!sbi->nls) { + pr_err("unable to load nls mapping " + "\"%s\"\n", p); + kfree(p); + return 0; + } } kfree(p); + have_iocharset = 1; break; case opt_decompose: clear_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
@@ -207,13 +214,10 @@ int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi) } done: - if (!sbi->nls) { - /* try utf8 first, as this is the old default behaviour */ - sbi->nls = load_nls("utf8"); - if (!sbi->nls) - sbi->nls = load_nls_default(); - if (!sbi->nls) - return 0; + if (!have_iocharset) { + /* use utf8, as this is the old default behaviour */ + pr_debug("using native UTF-8 without nls\n"); + /* no sbi->nls means that native UTF-8 code is used */ } return 1;
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index b9e3db3f855f..985662451bfc 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c@@ -403,11 +403,7 @@ static int hfsplus_fill_super(struct super_block *sb, void *data, int silent) /* temporarily use utf8 to correctly find the hidden dir below */ nls = sbi->nls; - sbi->nls = load_nls("utf8"); - if (!sbi->nls) { - pr_err("unable to load nls for utf8\n"); - goto out_unload_nls; - } + sbi->nls = NULL; /* Grab the volume header */ if (hfsplus_read_wrapper(sb)) {
@@ -585,7 +581,6 @@ static int hfsplus_fill_super(struct super_block *sb, void *data, int silent) } } - unload_nls(sbi->nls); sbi->nls = nls; return 0;
diff --git a/fs/hfsplus/unicode.c b/fs/hfsplus/unicode.c
index 73342c925a4b..1d8c31c5126f 100644
--- a/fs/hfsplus/unicode.c
+++ b/fs/hfsplus/unicode.c@@ -190,7 +190,12 @@ int hfsplus_uni2asc(struct super_block *sb, c0 = ':'; break; } - res = nls->uni2char(c0, op, len); + if (nls) + res = nls->uni2char(c0, op, len); + else (len > 0) + res = utf32_to_utf8(c0, op, len); + else + res = -ENAMETOOLONG; if (res < 0) { if (res == -ENAMETOOLONG) goto out;
@@ -233,7 +238,12 @@ int hfsplus_uni2asc(struct super_block *sb, cc = c0; } done: - res = nls->uni2char(cc, op, len); + if (nls) + res = nls->uni2char(cc, op, len); + else (len > 0) + res = utf32_to_utf8(cc, op, len); + else + res = -ENAMETOOLONG; if (res < 0) { if (res == -ENAMETOOLONG) goto out;
@@ -256,7 +266,22 @@ int hfsplus_uni2asc(struct super_block *sb, static inline int asc2unichar(struct super_block *sb, const char *astr, int len, wchar_t *uc) { - int size = HFSPLUS_SB(sb)->nls->char2uni(astr, len, uc); + struct nls_table *nls = HFSPLUS_SB(sb)->nls; + unicode_t u; + int size; + + if (nls) + size = nls->char2uni(astr, len, uc); + else { + size = utf8_to_utf32(astr, len, &u); + if (size >= 0) { + /* TODO: Add support for UTF-16 surrogate pairs */ + if (u <= MAX_WCHAR_T) + *uc = u; + else + size = -EINVAL; + } + } if (size <= 0) { *uc = '?'; size = 1;
diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
index e2855ceefd39..9b2653f08a5f 100644
--- a/fs/hfsplus/xattr.c
+++ b/fs/hfsplus/xattr.c@@ -425,7 +425,8 @@ int hfsplus_setxattr(struct inode *inode, const char *name, char *xattr_name; int res; - xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1, + xattr_name = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) * + HFSPLUS_ATTR_MAX_STRLEN + 1, GFP_KERNEL); if (!xattr_name) return -ENOMEM;
@@ -579,7 +580,8 @@ ssize_t hfsplus_getxattr(struct inode *inode, const char *name, int res; char *xattr_name; - xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1, + xattr_name = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) * + HFSPLUS_ATTR_MAX_STRLEN + 1, GFP_KERNEL); if (!xattr_name) return -ENOMEM;
@@ -699,8 +701,9 @@ 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); + strbuf = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) * + HFSPLUS_ATTR_MAX_STRLEN + XATTR_MAC_OSX_PREFIX_LEN + 1, + GFP_KERNEL); if (!strbuf) { res = -ENOMEM; goto out;
@@ -732,7 +735,8 @@ 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 = NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN; + xattr_name_len = (HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) + * HFSPLUS_ATTR_MAX_STRLEN; if (hfsplus_uni2asc(inode->i_sb, (const struct hfsplus_unistr *)&fd.key->attr.key_name, strbuf, &xattr_name_len)) {
diff --git a/fs/hfsplus/xattr_security.c b/fs/hfsplus/xattr_security.c
index c1c7a16cbf21..438ebcd1359b 100644
--- a/fs/hfsplus/xattr_security.c
+++ b/fs/hfsplus/xattr_security.c@@ -41,7 +41,8 @@ static int hfsplus_initxattrs(struct inode *inode, char *xattr_name; int err = 0; - xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1, + xattr_name = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) * + HFSPLUS_ATTR_MAX_STRLEN + 1, GFP_KERNEL); if (!xattr_name) return -ENOMEM;
--
2.20.1