netdev - Re: packet_sendmsg_spkt sleeping from invalid context

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]

Message-ID: <4B26AD65.1020004@gmail.com>
Date:	Mon, 14 Dec 2009 22:25:57 +0100
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Frederic Weisbecker <fweisbec@...il.com>
CC:	"David S. Miller" <davem@...emloft.net>,
	Neil Horman <nhorman@...driver.com>,
	Netdev <netdev@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: packet_sendmsg_spkt sleeping from invalid context

Le 14/12/2009 21:52, Frederic Weisbecker a écrit :
> 
> I also wonder. Are you using PREEMPT_RCU ?

Not at all :)

But yes, this is illegal to do the memcpy_fromiovec() in rcu_read_lock() context.

> That may explain why you haven't seen this issue because
> might_sleep() doesn't see you are in a rcu read locked
> section as preemption is not disabled, but it is illegal to
> voluntarily sleep in such area (although it's fine with
> preempt rcu) as doing so with non-prempt RCU config would barf.
> 
> I'm trying a patch to handle that.

As you want, I also have a patch testing right now :)
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html