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

2011/12/6 Erik Faye-Lund [off-list ref]:

2011/12/5 Nguyễn Thái Ngọc Duy [off-list ref]:

quoted

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 <redacted>
---
 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