Date:   Mon, 27 Feb 2023 11:23:59 -0800
From:   Jakub Kicinski <kuba@kernel.org>
To:     Fedor Pchelkin <pchelkin@ispras.ru>
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>,
        Guenter Roeck <groeck@google.com>,
        Martin Faltesek <mfaltesek@google.com>,
        Duoming Zhou <duoming@zju.edu.cn>,
        Samuel Ortiz <sameo@linux.intel.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Alexey Khoroshilov <khoroshilov@ispras.ru>,
        lvc-project@linuxtesting.org,
        syzbot+df64c0a2e8d68e78a4fa@syzkaller.appspotmail.com
Subject: Re: [PATCH] nfc: fix memory leak of se_io context in nfc_genl_se_io
Message-ID: <20230227112359.6df702e3@kernel.org>
In-Reply-To: <20230225105614.379382-1-pchelkin@ispras.ru>
References: <20230225105614.379382-1-pchelkin@ispras.ru>
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On Sat, 25 Feb 2023 13:56:14 +0300 Fedor Pchelkin wrote:
> The callback context for sending/receiving APDUs to/from the selected
> secure element is allocated inside nfc_genl_se_io and supposed to be
> eventually freed in se_io_cb callback function. However, there are several
> error paths where the bwi_timer is not charged to call se_io_cb later, and
> the cb_context is leaked.
> 
> The patch proposes to free the cb_context explicitly on those error paths.
> 
> At the moment we can't simply check 'dev->ops->se_io()' return value as it
> may be negative in both cases: when the timer was charged and was not.

FWIW this patch has already been applied, please send the next changes
on top:
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=25ff6f8a5a3b8dc48e8abda6f013e8cc4b14ffea