From: Karsten Graul <kgraul@linux.ibm.com>
To: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
linux-s390@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, Tony Lu <tonylu@linux.alibaba.com>
Cc: syzbot+4f322a6d84e991c38775@syzkaller.appspotmail.com
Subject: Re: [PATCH] net/smc: Use a mutex for locking "struct smc_pnettable"
Date: Wed, 23 Feb 2022 18:59:10 +0100 [thread overview]
Message-ID: <9725f86f-eabe-6aaf-0ef1-74138d895834@linux.ibm.com> (raw)
In-Reply-To: <20220223100252.22562-1-fmdefrancesco@gmail.com>
On 23/02/2022 11:02, Fabio M. De Francesco wrote:
> smc_pnetid_by_table_ib() uses read_lock() and then it calls smc_pnet_apply_ib()
> which, in turn, calls mutex_lock(&smc_ib_devices.mutex).
>
> read_lock() disables preemption. Therefore, the code acquires a mutex while in
> atomic context and it leads to a SAC bug.
>
> Fix this bug by replacing the rwlock with a mutex.
>
> Reported-and-tested-by: syzbot+4f322a6d84e991c38775@syzkaller.appspotmail.com
> Fixes: 64e28b52c7a6 ("net/smc: add pnet table namespace support")
> Confirmed-by: Tony Lu <tonylu@linux.alibaba.com>
> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
> ---
Thank you Fabio!
This should go to the net tree...
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
prev parent reply other threads:[~2022-02-23 17:59 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-23 10:02 [PATCH] net/smc: Use a mutex for locking "struct smc_pnettable" Fabio M. De Francesco
2022-02-23 17:59 ` Karsten Graul [this message]
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