Date:   Tue, 23 Apr 2019 10:57:54 -0700
From:   Matthias Kaehlcke <mka@chromium.org>
To:     Marcel Holtmann <marcel@holtmann.org>
Cc:     Johan Hedberg <johan.hedberg@gmail.com>,
        linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org,
        Balakrishna Godavarthi <bgodavar@codeaurora.org>,
        Hemantg <hemantg@codeaurora.org>,
        Rocky Liao <rjliao@codeaurora.org>
Subject: Re: [PATCH] Bluetooth: hci_qca: Fix crash with non-serdev devices
Message-ID: <20190423175754.GC112750@google.com>
References: <CAG5bF+TCPc=m_O33RHXHrt34T1Dz1zHLSkXfpxAoOTmrffGJ7w@mail.gmail.com>
 <32C292F9-34DF-436F-896E-A219D961218F@holtmann.org>
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On Tue, Apr 23, 2019 at 07:26:40PM +0200, Marcel Holtmann wrote:
> Hi Matthias,
> 
> > qca_set_baudrate() calls serdev_device_wait_until_sent() assuming that
> > the HCI is always associated with a serdev device. This isn't true for
> > ROME controllers instantiated through ldisc, where the call causes a
> > crash due to a NULL pointer dereferentiation. Only call the function
> > when we have a serdev device. The timeout for ROME devices at the end
> > of qca_set_baudrate() is long enough to be reasonably sure that the
> > command was sent.
> > 
> > Fixes: fa9ad876b8e0 ("Bluetooth: hci_qca: Add support for Qualcomm
> > Bluetooth chip wcn3990")
> > Reported-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
> > Reported-by: Rocky Liao <rjliao@codeaurora.org>
> > Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> > ---
> > drivers/bluetooth/hci_qca.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> > index 4ea995d610d2..714a6a16f9d5 100644
> > --- a/drivers/bluetooth/hci_qca.c
> > +++ b/drivers/bluetooth/hci_qca.c
> > @@ -1004,7 +1004,8 @@ static int qca_set_baudrate(struct hci_dev
> > *hdev, uint8_t baudrate)
> > 	while (!skb_queue_empty(&qca->txq))
> > 		usleep_range(100, 200);
> > 
> > -	serdev_device_wait_until_sent(hu->serdev,
> > +	if (hu->serdev)
> > +		serdev_device_wait_until_sent(hu->serdev,
> > 		      msecs_to_jiffies(CMD_TRANS_TIMEOUT_MS));
> 
> somehow I get a malformed patch when I try to apply it. Can you send a new version against bluetooth-next with all tags added.

Dunno what happened there, I'll send a new version with the tags in a
bit.

Thanks

Matthias