From: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
To: Jens Axboe <axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
Cc: linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
io-uring-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: io_uring vs in_compat_syscall()
Date: Mon, 20 Jul 2020 08:10:46 +0200 [thread overview]
Message-ID: <20200720061046.GA10678@lst.de> (raw)
Hi Jens,
I just found a (so far theoretical) issue with the io_uring submission
offloading to workqueues or threads. We have lots of places using
in_compat_syscall() to check if a syscall needs compat treatmenet.
While the biggest users is iocttl(), we also have a fair amount of
places using in_compat_task() in read and write methods, and these
will not do the wrong thing when used with io_uring under certain
conditions. I'm not sure how to best fix this, except for making sure
in_compat_syscall() returns true one way or another for these cases.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-arch@vger.kernel.org, linux-api@vger.kernel.org,
linux-kernel@vger.kernel.org, io-uring@vger.kernel.org
Subject: io_uring vs in_compat_syscall()
Date: Mon, 20 Jul 2020 08:10:46 +0200 [thread overview]
Message-ID: <20200720061046.GA10678@lst.de> (raw)
Message-ID: <20200720061046.MXflEx-26Y1ovM7Mk1xLsAvrJJ28kX_wZSyuYnzIDuM@z> (raw)
Hi Jens,
I just found a (so far theoretical) issue with the io_uring submission
offloading to workqueues or threads. We have lots of places using
in_compat_syscall() to check if a syscall needs compat treatmenet.
While the biggest users is iocttl(), we also have a fair amount of
places using in_compat_task() in read and write methods, and these
will not do the wrong thing when used with io_uring under certain
conditions. I'm not sure how to best fix this, except for making sure
in_compat_syscall() returns true one way or another for these cases.
next reply other threads:[~2020-07-20 6:10 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-20 6:10 Christoph Hellwig [this message]
2020-07-20 6:10 ` io_uring vs in_compat_syscall() Christoph Hellwig
2020-07-20 16:36 ` Jens Axboe
2020-07-20 16:36 ` Jens Axboe
2020-07-20 16:58 ` Andy Lutomirski
[not found] ` <BACE670C-6A65-4D86-BC5F-A7EA267C3140-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org>
2020-07-20 17:02 ` Jens Axboe
2020-07-20 17:02 ` Jens Axboe
2020-07-20 17:28 ` Andy Lutomirski
2020-07-20 17:28 ` Andy Lutomirski
2020-07-21 7:07 ` Christoph Hellwig
[not found] ` <20200721070709.GB11432-jcswGhMUV9g@public.gmane.org>
2020-07-21 14:31 ` Andy Lutomirski
2020-07-21 14:31 ` Andy Lutomirski
[not found] ` <CALCETrXWZBXZuCeRYvYY8AWG51e_P3bOeNeqc8zXPLOTDTHY0g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2020-07-21 14:34 ` Christoph Hellwig
2020-07-21 14:34 ` Christoph Hellwig
[not found] ` <20200721143412.GA8099-jcswGhMUV9g@public.gmane.org>
2020-07-21 17:25 ` Andy Lutomirski
2020-07-21 17:25 ` Andy Lutomirski
[not found] ` <CALCETrWMQpKe7jqw2t39yn4HgGhGTSEFGK6MPR4wPs=tBBhjbg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2020-07-22 6:30 ` Christoph Hellwig
2020-07-22 6:30 ` Christoph Hellwig
2020-07-22 8:39 ` David Laight
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