From a4a13f582c6d36b78b1c0459ee0b28f17bb2fb06 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Wed, 27 Apr 2016 22:22:20 +0800 Subject: [PATCH] f2fs: be aware of invalid filename length The filename length in dirent of may become zero-sized after random junk data injection, once encounter such dirent, find_target_dentry or f2fs_add_inline_entries will run into an infinite loop. So let f2fs being aware of that to avoid deadloop. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/dir.c | 14 +++++--------- fs/f2fs/inline.c | 14 ++++++-------- 2 files changed, 11 insertions(+), 17 deletions(-) diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index e90380d82214..3b1c14e4eeea 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -101,11 +101,6 @@ static struct f2fs_dir_entry *find_in_block(struct page *dentry_page, else kunmap(dentry_page); - /* - * For the most part, it should be a bug when name_len is zero. - * We stop here for figuring out where the bugs has occurred. - */ - f2fs_bug_on(F2FS_P_SB(dentry_page), d.max < 0); return de; } @@ -130,6 +125,11 @@ struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *fname, de = &d->dentry[bit_pos]; + if (unlikely(!de->name_len)) { + bit_pos++; + continue; + } + /* encrypted case */ de_name.name = d->filename[bit_pos]; de_name.len = le16_to_cpu(de->name_len); @@ -147,10 +147,6 @@ struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *fname, *max_slots = max_len; max_len = 0; - /* remain bug on condition */ - if (unlikely(!de->name_len)) - d->max = -1; - bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); } diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c index 772056587eb9..e61084cac5f1 100644 --- a/fs/f2fs/inline.c +++ b/fs/f2fs/inline.c @@ -303,11 +303,6 @@ struct f2fs_dir_entry *find_in_inline_dir(struct inode *dir, else f2fs_put_page(ipage, 0); - /* - * For the most part, it should be a bug when name_len is zero. - * We stop here for figuring out where the bugs has occurred. - */ - f2fs_bug_on(sbi, d.max < 0); return de; } @@ -437,6 +432,12 @@ static int f2fs_add_inline_entries(struct inode *dir, } de = &d.dentry[bit_pos]; + + if (unlikely(!de->name_len)) { + bit_pos++; + continue; + } + new_name.name = d.filename[bit_pos]; new_name.len = de->name_len; @@ -448,9 +449,6 @@ static int f2fs_add_inline_entries(struct inode *dir, if (err) goto punch_dentry_pages; - if (unlikely(!de->name_len)) - d.max = -1; - bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); } return 0;