linux-kernel - Re: [PATCH v3 0/2] iov_iter: allow iov_iter_get_pages

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: <20170205210151.GD13195@ZenIV.linux.org.uk>
Date:   Sun, 5 Feb 2017 21:01:51 +0000
From:   Al Viro <viro@...IV.linux.org.uk>
To:     Miklos Szeredi <miklos@...redi.hu>
Cc:     linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        Linux NFS list <linux-nfs@...r.kernel.org>,
        ceph-devel@...r.kernel.org, lustre-devel@...ts.lustre.org,
        v9fs-developer@...ts.sourceforge.net,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Jan Kara <jack@...e.cz>,
        Chris Wilson <chris@...is-wilson.co.uk>,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Jeff Layton <jlayton@...hat.com>
Subject: Re: [PATCH v3 0/2] iov_iter: allow iov_iter_get_pages_alloc to
 allocate more pages per call

On Sun, Feb 05, 2017 at 09:15:24PM +0100, Miklos Szeredi wrote:

> That case is fine.   But nothing guarantees that fuse_abort_conn()
> won't be called (in the non-deadlock case) when data is being copied
> to the request args.  Ending the request at such a point could easily
> lead to use after free,

So why not leave ending it to your fuse_dev_do_write()/fuse_dev_do_read()?
See the reply I'd just sent (your mail arrived while I'd been writing that
one - saw it only after I'd sent mine).

Basically, what if we keep FR_LOCKED through *all* fuse_dev_do_{read,write}(),
rather than dropping and regaining it many times and have fuse_abort_conn()
skip request_end() on FR_LOCKED ones?