Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH] io_uring: fix memory leak of UNIX domain socket inode
To:     Eric Biggers <ebiggers@kernel.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc:     davem@davemloft.net, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com,
        syzbot <syzbot+111cb28d9f583693aefa@syzkaller.appspotmail.com>
References: <0000000000005bc340058983fe8e@google.com>
 <20190612215843.91294-1-ebiggers@kernel.org>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <c8afa475-8ed9-e8ee-c66a-270bea7efad5@kernel.dk>
Date:   Thu, 13 Jun 2019 02:40:13 -0600
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.7.0
MIME-Version: 1.0
In-Reply-To: <20190612215843.91294-1-ebiggers@kernel.org>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 6/12/19 3:58 PM, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> Opening and closing an io_uring instance leaks a UNIX domain socket
> inode.  This is because the ->file of the io_uring instance's internal
> UNIX domain socket is set to point to the io_uring file, but then
> sock_release() sees the non-NULL ->file and assumes the inode reference
> is held by the file so doesn't call iput().  That's not the case here,
> since the reference is still meant to be held by the socket; the actual
> inode of the io_uring file is different.
> 
> Fix this leak by NULL-ing out ->file before releasing the socket.

Thanks, applied.

-- 
Jens Axboe