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From:   Keita Suzuki <keitasuzuki.park@sslab.ics.keio.ac.jp>
Date:   Fri, 10 Apr 2020 14:21:26 +0900
Message-ID: <CAEYrHjmy=R0x+zAcANDcTqx2qOhoUjy0Z2okxkjX1JHC3CgZ_A@mail.gmail.com>
Subject: Re: [PATCH] nfp: Fix memory leak in nfp_resource_acquire()
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     Kubota Takafumi <takafumi.kubota1012@sslab.ics.keio.ac.jp>,
        "David S. Miller" <davem@davemloft.net>,
        "open list:NETRONOME ETHERNET DRIVERS" <oss-drivers@netronome.com>,
        "open list:NETWORKING DRIVERS" <netdev@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
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Hi,

Thanks for reviewing.

I'll check back the runtime log and see what I can do.
Thanks.


2020=E5=B9=B44=E6=9C=8810=E6=97=A5(=E9=87=91) 4:32 Jakub Kicinski <kuba@ker=
nel.org>:
>
> On Thu,  9 Apr 2020 17:41:11 +0000 Keita Suzuki wrote:
> > This patch fixes a memory leak in nfp_resource_acquire(). res->mutex is
> > alllocated in nfp_resource_try_acquire(). However, when
> > msleep_interruptible() or time_is_before_eq_jiffies() fails, it falls
> > into err_fails path where res is freed, but res->mutex is not.
> >
> > Fix this by changing call to free to nfp_resource_release().
>
> I don't see a leak here. Maybe you could rephrase the description to
> make things clearer?
>
> AFAICS nfp_resource_try_acquire() calls nfp_cpp_mutex_free(res->mutex)
> if it's about to return an error. We can only hit msleep or time check
> if it returned an error.