Hi Sheng,
On 2018/11/23 20:11, Sheng Yong wrote:
> Hi, Jaegeuk and Chao,
>
> On 2018/11/15 15:50, Jaegeuk Kim wrote:
>> If namelen is corrupted to have very long value, fill_dentries can copy
>> wrong memory area.
>>
> Is there any scenario that could hit this corruption? Or this is triggered
I didn't see such issue in my test, I guess it may be caused by fuzzing test.
Thanks,
> by fuzzing injection?
>
> thanks,
> Sheng Yong
>
>> Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
>> ---
>> fs/f2fs/dir.c | 12 +++++++++++-
>> 1 file changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
>> index bacc667950b6..c0c845da12fa 100644
>> --- a/fs/f2fs/dir.c
>> +++ b/fs/f2fs/dir.c
>> @@ -808,6 +808,17 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct
>> f2fs_dentry_ptr *d,
>> de_name.name = d->filename[bit_pos];
>> de_name.len = le16_to_cpu(de->name_len);
>>
>> + /* check memory boundary before moving forward */
>> + bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
>> + if (unlikely(bit_pos > d->max)) {
>> + f2fs_msg(sbi->sb, KERN_WARNING,
>> + "%s: corrupted namelen=%d, run fsck to fix.",
>> + __func__, le16_to_cpu(de->name_len));
>> + set_sbi_flag(sbi, SBI_NEED_FSCK);
>> + err = -EINVAL;
>> + goto out;
>> + }
>> +
>> if (f2fs_encrypted_inode(d->inode)) {
>> int save_len = fstr->len;
>>
>> @@ -830,7 +841,6 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct
>> f2fs_dentry_ptr *d,
>> if (readdir_ra)
>> f2fs_ra_node_page(sbi, le32_to_cpu(de->ino));
>>
>> - bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
>> ctx->pos = start_pos + bit_pos;
>> }
>> out:
>>
>
>
>
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