Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) client-ip=23.128.96.34;
Message-ID: <a63a6936-8422-47d5-9fc5-5c40a9915665@gmail.com>
Date:   Wed, 1 Nov 2023 12:12:06 +0530
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH] jfs: fix shift-out-of-bounds in dbJoin
From:   Manas Ghandat <ghandatmanas@gmail.com>
To:     dave.kleikamp@oracle.com, shaggy@kernel.org
Cc:     Linux-kernel-mentees@lists.linuxfoundation.org,
        jfs-discussion@lists.sourceforge.net, linux-kernel@vger.kernel.org,
        syzbot+411debe54d318eaed386@syzkaller.appspotmail.com
References: <20231011143937.31996-1-ghandatmanas@gmail.com>
 <50a32ba6-0051-6b70-aa8a-f565f8119a69@gmail.com>
Content-Language: en-US
In-Reply-To: <50a32ba6-0051-6b70-aa8a-f565f8119a69@gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

Hi, can you please review this patch

On 16/10/23 20:30, Manas Ghandat wrote:
> Just a friendly ping :)
>
> On 11/10/23 20:09, Manas Ghandat wrote:
>> Currently while joining the leaf in a buddy system there is shift out
>> of bound error in calculation of BUDSIZE. Added the required check
>> to the BUDSIZE and fixed the documentation as well.
>>
>> Reported-by: syzbot+411debe54d318eaed386@syzkaller.appspotmail.com
>> Closes: https://syzkaller.appspot.com/bug?extid=411debe54d318eaed386
>> Signed-off-by: Manas Ghandat <ghandatmanas@gmail.com>
>> ---
>>   fs/jfs/jfs_dmap.c | 8 +++++++-
>>   1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
>> index 6b838d3ae7c2..baa97bda1c7a 100644
>> --- a/fs/jfs/jfs_dmap.c
>> +++ b/fs/jfs/jfs_dmap.c
>> @@ -2730,7 +2730,9 @@ static int dbBackSplit(dmtree_t * tp, int leafno)
>>    *    leafno    - the number of the leaf to be updated.
>>    *    newval    - the new value for the leaf.
>>    *
>> - * RETURN VALUES: none
>> + * RETURN VALUES:
>> + *  0        - success
>> + *    -EIO    - i/o error
>>    */
>>   static int dbJoin(dmtree_t * tp, int leafno, int newval)
>>   {
>> @@ -2757,6 +2759,10 @@ static int dbJoin(dmtree_t * tp, int leafno, 
>> int newval)
>>            * get the buddy size (number of words covered) of
>>            * the new value.
>>            */
>> +
>> +        if ((newval - tp->dmt_budmin) > BUDMIN)
>> +            return -EIO;
>> +
>>           budsz = BUDSIZE(newval, tp->dmt_budmin);
>>             /* try to join.