Re: mp4h: Strange? segfault problem

[Samuel Thibault]

Svante Signell, le Wed 28 Dec 2011 11:26:37 +0100, a écrit :
> On Wed, 2011-12-28 at 10:33 +0100, Samuel Thibault wrote:
> > Svante Signell, le Wed 28 Dec 2011 10:17:24 +0100, a écrit :
> > > On GNU/Linux shortening the resolvedname vector from PATH_MAX to 64
> > > results in a stack corruption. This is not nice, but since that vector
> > > is allocated on the stack, maybe it is more acceptable than an
> > > environment corruption. 
> > 
> > Well, this is not surprising to get crashes when cheating with PATH_MAX:
> > the kernel still thinks PATH_MAX is 4096, and thus thinks that the
> > buffer is actually 4096 bytes long, and thus happily overwrites whatever
> > is after it if userland doesn't make it so.
> 
> Ok, this comparison was maybe not the best. The main problem remains,
> for Hurd, how can a too short path string overwrite the environment
> vector of strings?

Because the environment is just after main's arguments.

Samuel