* [PATCH] firmware: arm_scmi: Free mailbox channels if probe fails
@ 2021-08-03 22:22 Rishabh Bhatnagar
2021-08-04 8:33 ` Cristian Marussi
0 siblings, 1 reply; 4+ messages in thread
From: Rishabh Bhatnagar @ 2021-08-03 22:22 UTC (permalink / raw)
To: sudeep.holla, cristian.marussi
Cc: linux-arm-kernel, linux-kernel, avajid, adharmap, Rishabh Bhatnagar
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>
---
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;
}
void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id)
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] firmware: arm_scmi: Free mailbox channels if probe fails
2021-08-03 22:22 [PATCH] firmware: arm_scmi: Free mailbox channels if probe fails Rishabh Bhatnagar
@ 2021-08-04 8:33 ` Cristian Marussi
2021-08-04 8:40 ` Cristian Marussi
0 siblings, 1 reply; 4+ messages in thread
From: Cristian Marussi @ 2021-08-04 8:33 UTC (permalink / raw)
To: Rishabh Bhatnagar
Cc: sudeep.holla, linux-arm-kernel, linux-kernel, avajid, adharmap
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
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] firmware: arm_scmi: Free mailbox channels if probe fails
2021-08-04 8:33 ` Cristian Marussi
@ 2021-08-04 8:40 ` Cristian Marussi
2021-08-04 17:29 ` rishabhb
0 siblings, 1 reply; 4+ messages in thread
From: Cristian Marussi @ 2021-08-04 8:40 UTC (permalink / raw)
To: Rishabh Bhatnagar
Cc: sudeep.holla, linux-arm-kernel, linux-kernel, avajid, adharmap
On Wed, Aug 04, 2021 at 09:33:58AM +0100, Cristian Marussi wrote:
> 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.
>
Hi again,
sorry forgot one thing.
> > ---
> > 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 ?
>
Maybe it could be worth at this point unifying this common "cleanup-all-channels"
logic shared between scmi_probe()-error-path and scmi_remove() into its own
helper function to call from both sites.
Thanks,
Cristian
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] firmware: arm_scmi: Free mailbox channels if probe fails
2021-08-04 8:40 ` Cristian Marussi
@ 2021-08-04 17:29 ` rishabhb
0 siblings, 0 replies; 4+ messages in thread
From: rishabhb @ 2021-08-04 17:29 UTC (permalink / raw)
To: Cristian Marussi
Cc: sudeep.holla, linux-arm-kernel, linux-kernel, avajid, adharmap
On 2021-08-04 01:40, Cristian Marussi wrote:
> On Wed, Aug 04, 2021 at 09:33:58AM +0100, Cristian Marussi wrote:
>> 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.
>>
>
> Hi again,
>
> sorry forgot one thing.
>
>> > ---
>> > 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 ?
>>
>
> Maybe it could be worth at this point unifying this common
> "cleanup-all-channels"
> logic shared between scmi_probe()-error-path and scmi_remove() into its
> own
> helper function to call from both sites.
>
> Thanks,
> Cristian
Thanks for the review. I'll move the cleanup to a common helper
function.
It makes sense to destroy tx/rx idrs. I didn't realize they allocate
memory
internally.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-08-03 22:22 [PATCH] firmware: arm_scmi: Free mailbox channels if probe fails Rishabh Bhatnagar
2021-08-04 8:33 ` Cristian Marussi
2021-08-04 8:40 ` Cristian Marussi
2021-08-04 17:29 ` rishabhb
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