Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH v2 0/2] iter revert problems
To:     Jens Axboe <axboe@kernel.dk>, 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.1628780390.git.asml.silence@gmail.com>
From:   Pavel Begunkov <asml.silence@gmail.com>
Message-ID: <3eaf5365-586d-700b-0277-e0889bfeb05d@gmail.com>
Date:   Sat, 21 Aug 2021 15:24:28 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.12.0
MIME-Version: 1.0
In-Reply-To: <cover.1628780390.git.asml.silence@gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 8/12/21 9:40 PM, Pavel Begunkov wrote:
> For the bug description see 2/2. 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.

We need to do something with this, hopefully soon.


> v2: don't fail it has been justly fully reverted
> 
> Pavel Begunkov (2):
>   iov_iter: mark truncated iters
>   io_uring: don't retry with truncated iter
> 
>  fs/io_uring.c       | 16 ++++++++++++++++
>  include/linux/uio.h |  5 ++++-
>  2 files changed, 20 insertions(+), 1 deletion(-)
> 

-- 
Pavel Begunkov