Subject: Re: [PATCH net] net/9p: Fix a potential socket leak in p9_socket_open

From: Al Viro <[email-masked]>
Date: Thu, 24 Nov 2022 16:15:37 +0000

On Thu, Nov 24, 2022 at 06:15:54PM +0900, [email-masked] 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 <[email-masked]>
on the leak fix.