linux-kernel - Re: anonymous mmap() and random heap allocation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 16 Jul 2010 11:59:34 +0200
From:	Mikael Pettersson <mikpe@...uu.se>
To:	Xianghua Xiao <xiaoxianghua@...il.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: anonymous mmap() and random heap allocation

Xianghua Xiao writes:
 > It seems mmap() can not do random allocation for malloc()/heap on
 > Linux, anyone used pax's 'mmap randonness' option for that? what's the
 > price for that?
 > 
 > I want to port openbsd's malloc() to linux to avoid heap
 > crashes(overrun/underrun), openbsd's malloc() can do random allocation
 > for security reasons, meanwhile it helps to avoid some
 > overrun/underrun crashes with no extra cost, the latter is what I'm
 > looking for.

You can implement this in user-space with existing kernel features.
1: place guard pages around mmap():ed data
2: parse /proc/self/maps and mmap(MAP_FIXED)
3: use a "safe" compiler or a dynamic binary instrumenter
4: use x86 segments (ugh!)
5: use a safe programming language
...
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/