linux-kernel - Re: [GIT PULL] Detaching mounts on unlink for 3.15

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20140417221456.GD18016@ZenIV.linux.org.uk>
Date:	Thu, 17 Apr 2014 23:14:56 +0100
From:	Al Viro <viro@...IV.linux.org.uk>
To:	"Eric W. Biederman" <ebiederm@...ssion.com>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	"Serge E. Hallyn" <serge@...lyn.com>,
	Linux-Fsdevel <linux-fsdevel@...r.kernel.org>,
	Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Andy Lutomirski <luto@...capital.net>,
	Rob Landley <rob@...dley.net>,
	Miklos Szeredi <miklos@...redi.hu>,
	Christoph Hellwig <hch@...radead.org>,
	Karel Zak <kzak@...hat.com>,
	"J. Bruce Fields" <bfields@...ldses.org>,
	Fengguang Wu <fengguang.wu@...el.com>, tytso@....edu
Subject: Re: [GIT PULL] Detaching mounts on unlink for 3.15

On Thu, Apr 17, 2014 at 11:12:03PM +0100, Al Viro wrote:
> 	* *KERNEL* vfsmounts; anything without MNT_INTERNAL is fair game
> as far as ordering of fs shutdown is concerned.  If it wasn't MNT_INTERNAL,
> and we'd done mntput() before destroying some data structures needed for

s/before/just before/, of course ;-)

> fs shutdown, we had been fucked anyway - no warranties that mntput() had
> been the final one.  Moreover, that means going through kern_unmount() or
> simple_release_fs().  Which is trivially dealt with by providing
> mntput_sync(mnt) that *will* wait and using it in those two.  Again, if
> we have an extra reference (e.g. stuffed into a struct file, etc.) -
> we can't rely on mntput() being final.
--
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/