Re: [PATCH] Set hard limit on delta chain depth

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 12/06/2011 01:17 PM, Erik Faye-Lund wrote:
> 2011/12/5 Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx>:
>> 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@xxxxxxxxx>
>> ---
>>  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...

I'm confused: is the data only ever read by the same host that generated
it?  Because if not, then the "creator" had better never be configured
to use a chain depth that the "reader" cannot handle.  This in turn
imply that there should be a common limit that is supported by all git
clients and is a documented part of the protocol.  (Or the code has to
be rewritten to use an explicit stack instead of recursion.)

Michael

-- 
Michael Haggerty
mhagger@xxxxxxxxxxxx
http://softwareswirl.blogspot.com/
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Kernel Development]     [Gcc Help]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [V4L]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]     [Fedora Users]