linux-kernel - Re: [PATCH 15/19] vfs: Add superblock notifications [ver #16]

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: <2031798.1582302800@warthog.procyon.org.uk>
Date:   Fri, 21 Feb 2020 16:33:20 +0000
From:   David Howells <dhowells@...hat.com>
To:     Jann Horn <jannh@...gle.com>
Cc:     dhowells@...hat.com, Al Viro <viro@...iv.linux.org.uk>,
        raven@...maw.net, Miklos Szeredi <mszeredi@...hat.com>,
        Christian Brauner <christian@...uner.io>,
        Linux API <linux-api@...r.kernel.org>,
        linux-fsdevel <linux-fsdevel@...r.kernel.org>,
        kernel list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 15/19] vfs: Add superblock notifications [ver #16]

Jann Horn <jannh@...gle.com> wrote:

> (And as in the other case, the s->s_count increment will probably have
> to be moved above the add_watch_to_object(), unless you hold the
> sb_lock around it?)

It shouldn't matter as I'm holding s->s_umount across the add and increment.
That prevents the watch from being removed: watch_sb() would have to get the
lock first to do that.  It also deactivate_locked_super() from removing all
the watchers.

I can move it before, but I probably have to drop s_umount before I can call
put_super().

David