linux-kernel - Re: fs: lockup on rename

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: <CA+55aFxfDgYsp9SAxWTy2sS0KLrErPUd06bEYJf=siCmaBu52w@mail.gmail.com>
Date:	Sun, 26 Oct 2014 16:33:11 -0700
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Al Viro <viro@...iv.linux.org.uk>
Cc:	Sasha Levin <sasha.levin@...cle.com>,
	linux-fsdevel <linux-fsdevel@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Dave Jones <davej@...hat.com>,
	"Eric W. Biederman" <ebiederm@...ssion.com>
Subject: Re: fs: lockup on rename_mutex in fs/dcache.c:1035

On Sun, Oct 26, 2014 at 2:57 PM, Al Viro <viro@...iv.linux.org.uk> wrote:
>  .. snip ..
> in d_walk(), __list_del() instead of list_del() in __dentry_kill(), d_u.d_child
> turning into d_child everywhere, while d_alias turns into d_u.d_alias...
>
> It looks like that way we would get no retries on the second pass.  Comments?

Since I missed the whole issue with d_child.next, I'm not sure any
comments from me would be helpful.

It does sound like trying to be more careful with d_child and using
d_alias instead is a good idea. d_alias is only used under the dentry
lock, and not in any horribly subtle situations, right? So that sounds
like a good change regardless of this particular fix - making the
union happen in a less nasty place..

                     Linus
--
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/