From: Jakub Kicinski <jakub.kicinski@netronome.com>
To: Karsten Graul <kgraul@linux.ibm.com>
Cc: davem@davemloft.net, netdev@vger.kernel.org,
linux-s390@vger.kernel.org, heiko.carstens@de.ibm.com,
raspl@linux.ibm.com, ubraun@linux.ibm.com
Subject: Re: [PATCH net] net/smc: add fallback check to connect()
Date: Sun, 15 Dec 2019 11:15:58 -0800 [thread overview]
Message-ID: <20191215111558.57dfdcf9@cakuba.netronome.com> (raw)
In-Reply-To: <20191212213558.10564-1-kgraul@linux.ibm.com>
On Thu, 12 Dec 2019 22:35:58 +0100, Karsten Graul wrote:
> From: Ursula Braun <ubraun@linux.ibm.com>
>
> FASTOPEN setsockopt() or sendmsg() may switch the SMC socket to fallback
> mode. Once fallback mode is active, the native TCP socket functions are
> called. Nevertheless there is a small race window, when FASTOPEN
> setsockopt/sendmsg runs in parallel to a connect(), and switch the
> socket into fallback mode before connect() takes the sock lock.
> Make sure the SMC-specific connect setup is omitted in this case.
>
> This way a syzbot-reported refcount problem is fixed, triggered by
> different threads running non-blocking connect() and FASTOPEN_KEY
> setsockopt.
>
> Reported-by: syzbot+96d3f9ff6a86d37e44c8@syzkaller.appspotmail.com
> Fixes: 6d6dd528d5af ("net/smc: fix refcount non-blocking connect() -part 2")
> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Applied, and queued for stable, thank you!
prev parent reply other threads:[~2019-12-15 19:16 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-12 21:35 [PATCH net] net/smc: add fallback check to connect() Karsten Graul
2019-12-15 19:15 ` Jakub Kicinski [this message]
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