udf: fix potential refcnt problem of nls module

When specifiying iocharset multiple times in a mount or once/multiple in
a remount, current option parsing may cause inaccurate refcount of nls
module.  Also, in the failure cleanup of option parsing, the condition
of calling unload_nls is not sufficient.

Signed-off-by: Chengguang Xu <cgxu519@icloud.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Chengguang Xu 2018-02-25 21:25:07 +08:00 committed by Jan Kara
parent d090990510
commit 785dffe1da

View File

@ -477,7 +477,6 @@ static int udf_parse_options(char *options, struct udf_options *uopt,
uopt->session = 0xFFFFFFFF;
uopt->lastblock = 0;
uopt->anchor = 0;
uopt->nls_map = NULL;
if (!options)
return 1;
@ -575,8 +574,12 @@ static int udf_parse_options(char *options, struct udf_options *uopt,
break;
#ifdef CONFIG_UDF_NLS
case Opt_iocharset:
if (!remount) {
if (uopt->nls_map)
unload_nls(uopt->nls_map);
uopt->nls_map = load_nls(args[0].from);
uopt->flags |= (1 << UDF_FLAG_NLS_MAP);
}
break;
#endif
case Opt_uforget:
@ -627,6 +630,7 @@ static int udf_remount_fs(struct super_block *sb, int *flags, char *options)
uopt.umask = sbi->s_umask;
uopt.fmode = sbi->s_fmode;
uopt.dmode = sbi->s_dmode;
uopt.nls_map = NULL;
if (!udf_parse_options(options, &uopt, true))
return -EINVAL;
@ -2095,6 +2099,7 @@ static int udf_fill_super(struct super_block *sb, void *options, int silent)
uopt.umask = 0;
uopt.fmode = UDF_INVALID_MODE;
uopt.dmode = UDF_INVALID_MODE;
uopt.nls_map = NULL;
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
if (!sbi)
@ -2275,8 +2280,8 @@ error_out:
iput(sbi->s_vat_inode);
parse_options_failure:
#ifdef CONFIG_UDF_NLS
if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP))
unload_nls(sbi->s_nls_map);
if (uopt.nls_map)
unload_nls(uopt.nls_map);
#endif
if (lvid_open)
udf_close_lvid(sb);