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Subject: Re: [PATCH v3 0/2] iter revert problems
To:     Pavel Begunkov <asml.silence@gmail.com>, io-uring@vger.kernel.org,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>
Cc:     Palash Oswal <oswalpalash@gmail.com>,
        Sudip Mukherjee <sudipm.mukherjee@gmail.com>,
        linux-kernel@vger.kernel.org,
        syzbot+9671693590ef5aad8953@syzkaller.appspotmail.com
References: <cover.1629713020.git.asml.silence@gmail.com>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <2a981061-5420-85dd-d41c-7ed36384465c@kernel.dk>
Date:   Mon, 23 Aug 2021 10:14:42 -0600
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On 8/23/21 4:18 AM, Pavel Begunkov wrote:
> iov_iter_revert() doesn't go well with iov_iter_truncate() in all
> cases, see 2/2 for the bug description. As mentioned there the current
> problems is because of generic_write_checks(), but there was also a
> similar case fixed in 5.12, which should have been triggerable by normal
> write(2)/read(2) and others.
> 
> It may be better to enforce reexpands as a long term solution, but for
> now this patchset is quickier and easier to backport.

Al, given the discussion from this weekend, are you fine with the first
patch? If so, would be great with an ack/review. Or, if you want to
funnel this for 5.14, you can add:

Reviewed-by: Jens Axboe <axboe@kernel.dk>

-- 
Jens Axboe