netdev - question on pktgen shutdown logic.

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-next>] [day] [month] [year] [list]

Message-ID: <519D519B.8040406@candelatech.com>
Date:	Wed, 22 May 2013 16:15:39 -0700
From:	Ben Greear <greearb@...delatech.com>
To:	netdev <netdev@...r.kernel.org>
Subject: question on pktgen shutdown logic.

While looking at pktgen.c in 3.9.3, I cannot explain how
it does not race on shutdown.

The thread worker checks for pktgen_exiting, and will bail out
of it's main loop and initiate cleanup if this is true.

The pg_net_exit sets the pktgen_exiting to true, and then
proceedes to call

		kthread_stop(t->tsk);
		kfree(t);

What I don't understand is what keeps the kfree(t) from happening
before the thread has noticed pktgen_exiting is set and properly
bailed out of it's loop and finished cleanup?

Thanks,
Ben

-- 
Ben Greear <greearb@...delatech.com>
Candela Technologies Inc  http://www.candelatech.com

--
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