From: Chao Yu <yuchao0@huawei.com>
To: Sheng Yong <shengyong1@huawei.com>,
Jaegeuk Kim <jaegeuk@kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-f2fs-devel@lists.sourceforge.net>
Subject: Re: [f2fs-dev] [PATCH] f2fs: check memory boundary by insane namelen
Date: Sat, 24 Nov 2018 17:59:20 +0800 [thread overview]
Message-ID: <1d801acd-ed1e-3593-45e6-ad71b27e4c7a@huawei.com> (raw)
In-Reply-To: <3d213d40-a4b0-6e60-87b2-81e66866ac4c@huawei.com>
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 <jaegeuk@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:
>>
>
>
>
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>
>
next prev parent reply other threads:[~2018-11-24 9:59 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-15 7:50 [PATCH] f2fs: check memory boundary by insane namelen Jaegeuk Kim
2018-11-17 2:27 ` [f2fs-dev] " Chao Yu
2018-11-23 12:11 ` Sheng Yong
2018-11-24 9:59 ` Chao Yu [this message]
2018-11-26 23:25 ` Jaegeuk Kim
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