From: Nguyen Thai Ngoc Duy <pclouds@gmail.com>
Date: Tue, 06 Dec 2011 12:32:41 GMT
Subject: Re: [PATCH] Set hard limit on delta chain depth
Message-ID: <CACsJy8BuUn4htSR6jAJfbueOshE6-YVV5dZGSWTGXbkuA0HO=A@mail.gmail.com>
In-Reply-To: <CABPQNSaE=TWGbBRMnthEuT181=XbOafPfgx88_JQnnQ6TiYyqw@mail.gmail.com>

2011/12/6 Erik Faye-Lund <kusmabite@gmail.com>:
> 2011/12/5 Nguyễn Thái Ngọc Duy <pclouds@gmail.com>:
>> Too deep delta chains can cause stack overflow in get_base_data(). Set
>> a hard limit so that index-pack does not run out of stack. Also stop
>> people from producing such a long delta chains using "pack-object
>> --depth=<too large>"
>>
>> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
>> ---
>>  I used to make very long delta chains and triggered this in index-pack.
>>  I did not care reporting because it's my fault anyway. Think again,
>>  index-pack is called at server side and a malicious client can
>>  trigger this. This patch does not improve the situation much, but at
>>  least we won't get sigsegv at server side.
>>
>
> Wouldn't it make more sense to make the limit a config option rather
> than a hard-coded value of 128 (which seems arbitrary to me)? After
> all, different platforms have different stack-limitations...

Then it'd make more sense to make a compile time config based on
platform. We could have a config option that can override the default,
but I really don't see the point of making long delta chains.
-- 
Duy