linux-kernel - Re: [RFC PATCH for-next 3/4] epoll: struct epoll support

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: <20140224115907.07092911@lwn.net>
Date:	Mon, 24 Feb 2014 11:59:07 -0700
From:	Jonathan Corbet <corbet@....net>
To:	Nathaniel Yazdani <n1ght.4nd.d4y@...il.com>
Cc:	viro@...iv.linux.org.uk, linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH for-next 3/4] epoll: struct epoll support

So I was just looking things over quickly, and something jumped out at
me.  In ep_control():

> +	} else if (!(*io) && epi) {
> +		/* delete this eventpoll entry */
> +		if (is_file_epoll(target)) {
> +			tep = target->private_data;
> +			mutex_lock_nested(&tep->mtx, 1);
> +		}
> +		if (is_file_epoll(target))
> +			mutex_lock_nested(&tep->mtx, 1);

How could that possibly work?  I can't imagine tep->mtx is going to
react well to being locked a second time...

jon
--
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/