From f1cfdec17c27db8461d76cd37edf4bf7f1bc64d1 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Fri, 12 Feb 2016 14:29:28 -0800 Subject: f2fs: avoid garbage lenghs in dentries This patch fixes to eliminate garbage name lengths in dentries in order to provide correct answers of readdir. For example, if a valid dentry consists of: bitmap : 1 1 1 1 len : 32 0 x 0, readdir can start with second bit_pos having len = 0. Or, it can start with third bit_pos having garbage. In both of cases, we should avoid to try filling dentries. So, this patch not only removes any garbage length, but also avoid entering zero length case in readdir. Signed-off-by: Jaegeuk Kim --- fs/f2fs/dir.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index 7a4c742aa..547d3477d 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -513,8 +513,12 @@ void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d, memcpy(d->filename[bit_pos], name->name, name->len); de->ino = cpu_to_le32(ino); set_de_type(de, mode); - for (i = 0; i < slots; i++) + for (i = 0; i < slots; i++) { test_and_set_bit_le(bit_pos + i, (void *)d->bitmap); + /* avoid wrong garbage data for readdir */ + if (i) + (de + i)->name_len = 0; + } } /* @@ -797,6 +801,11 @@ bool f2fs_fill_dentries(struct file *file, void *dirent, filldir_t filldir, de = &d->dentry[bit_pos]; + if (de->name_len == 0) { + bit_pos++; + continue; + } + if (types && de->file_type < F2FS_FT_MAX) d_type = types[de->file_type]; -- cgit v1.2.3