From: Al Viro <[email protected]>
To: Jens Axboe <[email protected]>
Cc: Pavel Begunkov <[email protected]>,
[email protected], [email protected],
Linus Torvalds <[email protected]>
Subject: Re: [PATCH 3/3] io_uring: refactor io_sq_offload_create()
Date: Fri, 23 Jul 2021 19:00:40 +0000 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On Fri, Jul 23, 2021 at 11:56:29AM -0600, Jens Axboe wrote:
> Will send out two patches for this. Note that I don't see this being a
> real issue, as we explicitly gave the ring fd to another task, and being
> that this is purely for read/write, it would result in -EFAULT anyway.
You do realize that ->release() might come from seriously unexpected places,
right? E.g. recvmsg() by something that doesn't expect SCM_RIGHTS attached
to it will end up with all struct file references stashed into the sucker
dropped, and if by that time that's the last reference - welcome to ->release()
run as soon as recepient hits task_work_run().
What's more, if you stash that into garbage for unix_gc() to pick, *any*
process closing an AF_UNIX socket might end up running your ->release().
So you really do *not* want to spawn any threads there, let alone
possibly exfiltrating memory contents of happy recepient of your present...
next prev parent reply other threads:[~2021-07-23 19:02 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-20 11:03 [PATCH 0/3] small 5.13 cleanups Pavel Begunkov
2021-04-20 11:03 ` [PATCH 1/3] io_uring: move inflight un-tracking into cleanup Pavel Begunkov
2021-04-20 11:03 ` [PATCH 2/3] io_uring: safer sq_creds putting Pavel Begunkov
2021-04-20 11:03 ` [PATCH 3/3] io_uring: refactor io_sq_offload_create() Pavel Begunkov
2021-07-22 21:59 ` Al Viro
2021-07-22 23:06 ` Jens Axboe
2021-07-22 23:30 ` Al Viro
2021-07-22 23:42 ` Jens Axboe
2021-07-23 0:10 ` Al Viro
2021-07-23 0:12 ` Al Viro
2021-07-23 16:17 ` Jens Axboe
2021-07-23 17:11 ` Al Viro
2021-07-23 17:32 ` Jens Axboe
2021-07-23 17:36 ` Jens Axboe
2021-07-23 17:56 ` Jens Axboe
2021-07-23 19:00 ` Al Viro [this message]
2021-07-23 20:10 ` Jens Axboe
2021-07-23 20:24 ` Al Viro
2021-07-23 22:32 ` Jens Axboe
2021-07-23 20:19 ` Al Viro
2021-07-23 23:45 ` Matthew Wilcox
2021-07-23 23:57 ` Jens Axboe
2021-07-24 1:31 ` Al Viro
2021-07-23 0:03 ` Al Viro
2021-07-23 9:59 ` Pavel Begunkov
2021-04-20 18:55 ` [PATCH 0/3] small 5.13 cleanups Jens Axboe
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