[RFC PATCH 12/20] hfs: Do not use broken utf8 NLS table for iocharset=utf8 mount option
From: Pali Rohár <pali@kernel.org>
Date: 2021-08-08 16:25:44
Also in:
linux-cifs, lkml
Subsystem:
filesystems (vfs and infrastructure), hfs 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. When iochatset=utf8 is used then set hsb->nls_io 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/hfs/super.c | 33 ++++++++++++++++++++++----------- fs/hfs/trans.c | 24 ++++++++++++++++++++---- 2 files changed, 42 insertions(+), 15 deletions(-)
diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index 86bc46746c7f..076308df41cf 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c@@ -149,10 +149,13 @@ static int hfs_show_options(struct seq_file *seq, struct dentry *root) seq_printf(seq, ",part=%u", sbi->part); if (sbi->session >= 0) seq_printf(seq, ",session=%u", sbi->session); - if (sbi->nls_disk) + if (sbi->nls_disk) { seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset); - if (sbi->nls_io) - seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset); + if (sbi->nls_io) + seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset); + else + seq_puts(seq, ",iocharset=utf8"); + } if (sbi->s_quiet) seq_printf(seq, ",quiet"); return 0;
@@ -225,6 +228,7 @@ static int parse_options(char *options, struct hfs_sb_info *hsb) char *p; substring_t args[MAX_OPT_ARGS]; int tmp, token; + int have_iocharset; /* initialize the sb with defaults */ hsb->s_uid = current_uid();
@@ -239,6 +243,8 @@ static int parse_options(char *options, struct hfs_sb_info *hsb) if (!options) return 1; + have_iocharset = 0; + while ((p = strsep(&options, ",")) != NULL) { if (!*p) continue;
@@ -332,18 +338,22 @@ static int parse_options(char *options, struct hfs_sb_info *hsb) kfree(p); break; case opt_iocharset: - if (hsb->nls_io) { + if (have_iocharset) { pr_err("unable to change iocharset\n"); return 0; } p = match_strdup(&args[0]); - if (p) - hsb->nls_io = load_nls(p); - if (!hsb->nls_io) { - pr_err("unable to load iocharset \"%s\"\n", p); - kfree(p); + if (!p) return 0; + if (strcmp(p, "utf8") != 0) { + hsb->nls_io = load_nls(p); + if (!hsb->nls_io) { + pr_err("unable to load iocharset \"%s\"\n", p); + kfree(p); + return 0; + } } + have_iocharset = 1; kfree(p); break; default:
@@ -351,7 +361,7 @@ static int parse_options(char *options, struct hfs_sb_info *hsb) } } - if (hsb->nls_io && !hsb->nls_disk) { + if (have_iocharset && !hsb->nls_disk) { /* * Previous version of hfs driver did something unexpected: * When codepage was not defined but iocharset was then
@@ -382,7 +392,8 @@ static int parse_options(char *options, struct hfs_sb_info *hsb) return 0; } } - if (hsb->nls_disk && !hsb->nls_io) { + if (hsb->nls_disk && + !have_iocharset && strcmp(CONFIG_NLS_DEFAULT, "utf8") != 0) { hsb->nls_io = load_nls_default(); if (!hsb->nls_io) { pr_err("unable to load default iocharset\n");
diff --git a/fs/hfs/trans.c b/fs/hfs/trans.c
index c75682c61b06..bff8e54003ab 100644
--- a/fs/hfs/trans.c
+++ b/fs/hfs/trans.c@@ -44,7 +44,7 @@ int hfs_mac2asc(struct super_block *sb, char *out, const struct hfs_name *in) srclen = HFS_NAMELEN; dst = out; dstlen = HFS_MAX_NAMELEN; - if (nls_io) { + if (nls_disk) { wchar_t ch; while (srclen > 0) {
@@ -57,7 +57,12 @@ int hfs_mac2asc(struct super_block *sb, char *out, const struct hfs_name *in) srclen -= size; if (ch == '/') ch = ':'; - size = nls_io->uni2char(ch, dst, dstlen); + if (nls_io) + size = nls_io->uni2char(ch, dst, dstlen); + else if (dstlen > 0) + size = utf32_to_utf8(ch, dst, dstlen); + else + size = -ENAMETOOLONG; if (size < 0) { if (size == -ENAMETOOLONG) goto out;
@@ -101,11 +106,22 @@ void hfs_asc2mac(struct super_block *sb, struct hfs_name *out, const struct qstr srclen = in->len; dst = out->name; dstlen = HFS_NAMELEN; - if (nls_io) { + if (nls_disk) { wchar_t ch; + unicode_t u; while (srclen > 0) { - size = nls_io->char2uni(src, srclen, &ch); + if (nls_io) + size = nls_io->char2uni(src, srclen, &ch); + else { + size = utf8_to_utf32(str, strlen, &u); + if (size >= 0) { + if (u <= MAX_WCHAR_T) + ch = u; + else + size = -EINVAL; + } + } if (size < 0) { ch = '?'; size = 1;
--
2.20.1