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Date:   Thu, 24 Nov 2022 16:15:37 +0000
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     asmadeus@codewreck.org
Cc:     Wang Hai <wanghai38@huawei.com>, ericvh@gmail.com,
        lucho@ionkov.net, linux_oss@crudebyte.com, davem@davemloft.net,
        edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
        v9fs-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org
Subject: Re: [PATCH net] net/9p: Fix a potential socket leak in p9_socket_open
Message-ID: <Y3+YqUbLXZ1ouynB@ZenIV>
References: <20221124081005.66579-1-wanghai38@huawei.com>
 <Y382Spkkzt+i86e8@codewreck.org>
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On Thu, Nov 24, 2022 at 06:15:54PM +0900, asmadeus@codewreck.org wrote:
> Wang Hai wrote on Thu, Nov 24, 2022 at 04:10:05PM +0800:
> > Both p9_fd_create_tcp() and p9_fd_create_unix() will call
> > p9_socket_open(). If the creation of p9_trans_fd fails,
> > p9_fd_create_tcp() and p9_fd_create_unix() will return an
> > error directly instead of releasing the cscoket, which will
> 
> (typo, socket or csocket -- I'll fix this on applying)
> 
> > result in a socket leak.
> > 
> > This patch adds sock_release() to fix the leak issue.
> 
> Thanks, it looks good to me.
> A bit confusing that sock_alloc_files() calls sock_release() itself on
> failure, but that means this one's safe at least...

sock_alloc_file() unconditionally consumes socket reference;
either it is transferred to new struct file it returns, or
it's dropped.  Makes for simpler logics in callers...
FWIW,
ACKed-by: Al Viro <viro@zeniv.linux.org.uk>
on the leak fix.