linux-kernel - Re: [linux-next-20130422] Bug in SLAB?

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:	Tue, 2 Jul 2013 21:49:26 +0900
From:	Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>
To:	akpm@...ux-foundation.org
Cc:	cl@...ux.com, glommer@...allels.com, penberg@...nel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [linux-next-20130422] Bug in SLAB?

Andrew Morton wrote:
> Look, I'll make this easier:
> 
> : Subject: slab: fix init_lock_keys
> : 
> : In 3.10 kernels with CONFIG_LOCKDEP=y on architectures with
> : PAGE_SHIFT + MAX_ORDER > 26 such as [architecture goes here], the kernel does
> : [x] when the user does [y].
> :
> : init_lock_keys() goes too far in initializing values in kmalloc_caches
> : because it assumed that the size of the kmalloc array goes up to
> : MAX_ORDER.  However, the size of the kmalloc array for SLAB may be
> : restricted due to increased page sizes or CONFIG_FORCE_MAX_ZONEORDER.
> :
> : Fix this by [z].
> 
> 
> Please fill in the text within [].
> 
OK. I made from http://marc.info/?l=linux-kernel&m=136810234704350&w=2 .
-----
Some architectures (e.g. powerpc built with CONFIG_PPC_256K_PAGES=y
CONFIG_FORCE_MAX_ZONEORDER=11) get PAGE_SHIFT + MAX_ORDER > 26.

In 3.10 kernels, CONFIG_LOCKDEP=y with PAGE_SHIFT + MAX_ORDER > 26 makes
init_lock_keys() dereference beyond kmalloc_caches[26].
This leads to an unbootable system (kernel panic at initializing SLAB)
if one of kmalloc_caches[26...PAGE_SHIFT+MAX_ORDER-1] is not NULL.

Fix this by making sure that init_lock_keys() does not dereference beyond
kmalloc_caches[26] arrays.
-----
--
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/