Messages in this thread | | | Date | Wed, 4 Aug 2021 09:33:58 +0100 | From | Cristian Marussi <> | Subject | Re: [PATCH] firmware: arm_scmi: Free mailbox channels if probe fails |
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On Tue, Aug 03, 2021 at 03:22:22PM -0700, Rishabh Bhatnagar wrote: > Mailbox channels for the base protocol are setup during probe. > There can be a scenario where probe fails to acquire the base > protocol due to a timeout leading to cleaning up of all device > managed memory including the scmi_mailbox structure setup during > mailbox_chan_setup function. > [ 12.735104]arm-scmi soc:qcom,scmi: timed out in resp(caller: version_get+0x84/0x140) > [ 12.735224]arm-scmi soc:qcom,scmi: unable to communicate with SCMI > [ 12.735947]arm-scmi: probe of soc:qcom,scmi failed with error -110 > > Now when a message arrives at cpu slightly after the timeout, the mailbox > controller will try to call the rx_callback of the client and might end > up accessing freed memory. > [ 12.758363][ C0] Call trace: > [ 12.758367][ C0] rx_callback+0x24/0x160 > [ 12.758372][ C0] mbox_chan_received_data+0x44/0x94 > [ 12.758386][ C0] __handle_irq_event_percpu+0xd4/0x240 > This patch frees the mailbox channels setup during probe and adds some more > error handling in case the probe fails. > > Change-Id: I1214ec2c4c92c4a3ca5fa73de11e0e403b13b46a > Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
Hi Rishabh,
Good catch, thanks for this.
> --- > drivers/firmware/arm_scmi/driver.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c > index 9b2e8d4..518c7b9 100644 > --- a/drivers/firmware/arm_scmi/driver.c > +++ b/drivers/firmware/arm_scmi/driver.c > @@ -1430,7 +1430,7 @@ static int scmi_probe(struct platform_device *pdev) > > ret = scmi_xfer_info_init(info); > if (ret) > - return ret; > + goto clear_txrx_setup; > > if (scmi_notification_init(handle)) > dev_err(dev, "SCMI Notifications NOT available.\n"); > @@ -1443,7 +1443,7 @@ static int scmi_probe(struct platform_device *pdev) > ret = scmi_protocol_acquire(handle, SCMI_PROTOCOL_BASE); > if (ret) { > dev_err(dev, "unable to communicate with SCMI\n"); > - return ret; > + goto notification_exit; > } > > mutex_lock(&scmi_list_mutex); > @@ -1482,6 +1482,13 @@ static int scmi_probe(struct platform_device *pdev) > } > > return 0; > + > +notification_exit: > + scmi_notification_exit(&info->handle); > +clear_txrx_setup: > + idr_for_each(&info->tx_idr, info->desc->ops->chan_free, &info->tx_idr); > + idr_for_each(&info->rx_idr, info->desc->ops->chan_free, &info->rx_idr); > + return ret; > } >
Shouldn't we also clear the internal IDRs memory allocs after these idr_for_each() adding a couple of:
idr_destroy(&info->tx_idr);
idr_destroy(&info->rx_idr);
like scmi_remove() does ?
Thanks, Cristian
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