linux-kernel - Re: netfilter: Hung task

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] [day] [month] [year] [list]

Date:	Mon, 19 Mar 2012 15:03:14 -0500 (CDT)
From:	Christoph Lameter <cl@...ux.com>
To:	Sasha Levin <levinsasha928@...il.com>
cc:	Pablo Neira Ayuso <pablo@...filter.org>, kaber@...sh.net,
	davem@...emloft.net, Dave Jones <davej@...hat.com>,
	netfilter-devel@...r.kernel.org,
	"linux-kernel@...r.kernel.org List" <linux-kernel@...r.kernel.org>,
	netdev@...r.kernel.org
Subject: Re: netfilter: Hung task

On Mon, 19 Mar 2012, Sasha Levin wrote:

> lockdep listed all the held locks there.

None of the locks listed are slub locks.

> I've mentioned that it looks very similar to
> https://lkml.org/lkml/2012/1/14/45 where the userspace helper tried to
> read from the sysfs files, but got into a deadlock since the kernel
> side held them before it called the usermode helper.

Ah yes. In that case slub held a semaphore. Code was changed since then to
no longer hold a semaphore when calling into sysfs.

The uevent handler can execute arbitrary user space code. Do you have to
hold locks while calling kmem_cache_destroy?


--
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/