Arm SCMI fixes for v6.12(part 2)

Couple of fixes to address slab-use-after-free in scmi_bus_notifier()
via scmi_dev->name and possible incorrect clear channel transport
operation on A2P channel if some sort of P2A only messages are initiated
on A2P channel(occurs when stress tested passing /dev/random to the
channel).

Apart from this, there are fixes to address missing "arm" prefix in the
recently added property max-rx-timeout-ms which was missed in the review
but was identified when further additions to the same binding were
getting reviewed.

* tag 'scmi-fixes-6.12-2' of https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  firmware: arm_scmi: Use vendor string in max-rx-timeout-ms
  dt-bindings: firmware: arm,scmi: Add missing vendor string
  firmware: arm_scmi: Reject clear channel request on A2P
  firmware: arm_scmi: Fix slab-use-after-free in scmi_bus_notifier()

Link: https://lore.kernel.org/r/20241031172734.3109140-1-sudeep.holla@arm.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Arnd Bergmann
2024-11-01 15:48:06 +01:00
4 changed files with 15 additions and 6 deletions

View File

@@ -124,7 +124,7 @@ properties:
atomic mode of operation, even if requested.
default: 0
max-rx-timeout-ms:
arm,max-rx-timeout-ms:
description:
An optional time value, expressed in milliseconds, representing the
transport maximum timeout value for the receive channel. The value should

View File

@@ -325,7 +325,10 @@ EXPORT_SYMBOL_GPL(scmi_driver_unregister);
static void scmi_device_release(struct device *dev)
{
kfree(to_scmi_dev(dev));
struct scmi_device *scmi_dev = to_scmi_dev(dev);
kfree_const(scmi_dev->name);
kfree(scmi_dev);
}
static void __scmi_device_destroy(struct scmi_device *scmi_dev)
@@ -338,7 +341,6 @@ static void __scmi_device_destroy(struct scmi_device *scmi_dev)
if (scmi_dev->protocol_id == SCMI_PROTOCOL_SYSTEM)
atomic_set(&scmi_syspower_registered, 0);
kfree_const(scmi_dev->name);
ida_free(&scmi_bus_id, scmi_dev->id);
device_unregister(&scmi_dev->dev);
}
@@ -410,7 +412,6 @@ __scmi_device_create(struct device_node *np, struct device *parent,
return scmi_dev;
put_dev:
kfree_const(scmi_dev->name);
put_device(&scmi_dev->dev);
ida_free(&scmi_bus_id, id);
return NULL;

View File

@@ -163,6 +163,7 @@ void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id);
* used to initialize this channel
* @dev: Reference to device in the SCMI hierarchy corresponding to this
* channel
* @is_p2a: A flag to identify a channel as P2A (RX)
* @rx_timeout_ms: The configured RX timeout in milliseconds.
* @handle: Pointer to SCMI entity handle
* @no_completion_irq: Flag to indicate that this channel has no completion
@@ -174,6 +175,7 @@ void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id);
struct scmi_chan_info {
int id;
struct device *dev;
bool is_p2a;
unsigned int rx_timeout_ms;
struct scmi_handle *handle;
bool no_completion_irq;

View File

@@ -1048,6 +1048,11 @@ static inline void scmi_xfer_command_release(struct scmi_info *info,
static inline void scmi_clear_channel(struct scmi_info *info,
struct scmi_chan_info *cinfo)
{
if (!cinfo->is_p2a) {
dev_warn(cinfo->dev, "Invalid clear on A2P channel !\n");
return;
}
if (info->desc->ops->clear_channel)
info->desc->ops->clear_channel(cinfo);
}
@@ -2638,6 +2643,7 @@ static int scmi_chan_setup(struct scmi_info *info, struct device_node *of_node,
if (!cinfo)
return -ENOMEM;
cinfo->is_p2a = !tx;
cinfo->rx_timeout_ms = info->desc->max_rx_timeout_ms;
/* Create a unique name for this transport device */
@@ -3042,10 +3048,10 @@ static const struct scmi_desc *scmi_transport_setup(struct device *dev)
dev_info(dev, "Using %s\n", dev_driver_string(trans->supplier));
ret = of_property_read_u32(dev->of_node, "max-rx-timeout-ms",
ret = of_property_read_u32(dev->of_node, "arm,max-rx-timeout-ms",
&trans->desc->max_rx_timeout_ms);
if (ret && ret != -EINVAL)
dev_err(dev, "Malformed max-rx-timeout-ms DT property.\n");
dev_err(dev, "Malformed arm,max-rx-timeout-ms DT property.\n");
dev_info(dev, "SCMI max-rx-timeout: %dms\n",
trans->desc->max_rx_timeout_ms);