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  PHC 
Open Source and information security mailing list archives
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Fri, 20 Jan 2012 12:40:32 -0800
From: (Eric W. Biederman)
To:	Christoph Lameter <>
Cc:	Eric Dumazet <>,
	Sasha Levin <>,
	Dave Jones <>, davem <>,
	Pekka Enberg <>,
	Matt Mackall <>,,, linux-kernel <>,
	linux-mm <>,,
	netdev <>
Subject: Re: Hung task when calling clone() due to netfilter/slab

Christoph Lameter <> writes:

> On Thu, 19 Jan 2012, Eric W. Biederman wrote:
>> On the flip side removing from sysfs with locks held must be done
>> carefully, and as a default I would recommend not to hold locks over
>> removing things from sysfs.  As removal blocks waiting for all of the
>> callers into sysfs those sysfs attributes to complete.
>> It looks like you are ok on the removal because none of the sysfs
>> attributes appear to take the slub_lock, just /proc/slabinfo.  But
>> it does look like playing with fire.
> Ok then I guess my last patch is needed to make sysfs operations safe.
> It may be good to audit the kernel for locks being held while calling
> sysfs functions. Isnt there a lockdep check that ensures that no locks are
> held?

I don't see a no locks are held check but call_usermodehelper in the
blocking case could certainly use one.

For the sysfs remove case lockdep should work.

To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists