> The current implementation doesn't care NameLength when extracting the
> name from Name dir-entries, so the name may be incorrect.
> (Without null-termination, Insufficient Name dir-entry, etc) Add a
> NameLength check when extracting the name from Name dir-entries to extract
> correct name.
> And, change to get the information of file/stream-ext dir-entries via the
> member variable of exfat_entry_set_cache.
>
> ** This patch depends on:
> '[PATCH v3] exfat: integrates dir-entry getting and validation'.
>
> Signed-off-by: Tetsuhiro Kohada <kohada.t2@xxxxxxxxx>
> ---
> fs/exfat/dir.c | 81 ++++++++++++++++++++++++--------------------------
> 1 file changed, 39 insertions(+), 42 deletions(-)
>
> diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index
> 91cdbede0fd1..545bb73b95e9 100644
> --- a/fs/exfat/dir.c
> +++ b/fs/exfat/dir.c
> @@ -28,16 +28,15 @@ static int exfat_extract_uni_name(struct exfat_dentry
> *ep,
>
> }
>
> -static void exfat_get_uniname_from_ext_entry(struct super_block *sb,
> - struct exfat_chain *p_dir, int entry, unsigned short
> *uniname)
> +static int exfat_get_uniname_from_name_entries(struct
> exfat_entry_set_cache *es,
> + struct exfat_uni_name *uniname)
> {
> - int i;
> - struct exfat_entry_set_cache *es;
> + int n, l, i;
> struct exfat_dentry *ep;
>
> - es = exfat_get_dentry_set(sb, p_dir, entry, ES_ALL_ENTRIES);
> - if (!es)
> - return;
> + uniname->name_len = es->de_stream->name_len;
> + if (uniname->name_len == 0)
> + return -EIO;
-EINVAL looks better.
>
> /*
> * First entry : file entry
> @@ -45,14 +44,15 @@ static void exfat_get_uniname_from_ext_entry(struct
> super_block *sb,
> * Third entry : first file-name entry
> * So, the index of first file-name dentry should start from 2.
> */
> -
> - i = 2;
> - while ((ep = exfat_get_validated_dentry(es, i++, TYPE_NAME))) {
> - exfat_extract_uni_name(ep, uniname);
> - uniname += EXFAT_FILE_NAME_LEN;
> + for (l = 0, n = 2; l < uniname->name_len; n++) {
> + ep = exfat_get_validated_dentry(es, n, TYPE_NAME);
> + if (!ep)
> + return -EIO;
> + for (i = 0; l < uniname->name_len && i <
EXFAT_FILE_NAME_LEN;
> i++, l++)
> + uniname->name[l] = le16_to_cpu(ep-
> >dentry.name.unicode_0_14[i]);
Looks good.
> }
> -
> - exfat_free_dentry_set(es, false);
> + uniname->name[l] = 0;
> + return 0;
> }
>
> /* read a directory entry from the opened directory */ @@ -63,6 +63,7 @@
> static int exfat_readdir(struct inode *inode, struct exfat_dir_entry
> *dir_entry)
[snip]
> - *uni_name.name = 0x0;
> - exfat_get_uniname_from_ext_entry(sb, &dir, dentry,
> - uni_name.name);
> + dir_entry->size = le64_to_cpu(es->de_stream-
> >valid_size);
> +
> + exfat_get_uniname_from_name_entries(es, &uni_name);
Modified function has a return value.
It would be better to check the return value.
> exfat_utf16_to_nls(sb, &uni_name,
> dir_entry->namebuf.lfn,
> dir_entry->namebuf.lfnbuf_len);
> - brelse(bh);
>
> - ep = exfat_get_dentry(sb, &clu, i + 1, &bh, NULL);
> - if (!ep)
> - return -EIO;
> - dir_entry->size =
> - le64_to_cpu(ep->dentry.stream.valid_size);
> - brelse(bh);
> + exfat_free_dentry_set(es, false);
>
> ei->hint_bmap.off = dentry >> dentries_per_clu_bits;
> ei->hint_bmap.clu = clu.dir;
> --
> 2.25.1
