[PATCH] staging: vchiq: Avoid mixing bulk_userdata kernel and userspace pointer

From: Umang Jain
Date: Tue Jul 30 2024 - 13:12:16 EST

Next message: Keith Busch: "Re: [PATCH] nvme-pci: add missing condition check for existence of mapped data"
Previous message: tip-bot2 for Thomas Gleixner: " [tip: timers/core] selftests/timers/posix_timers: Simplify error handling"
Next in thread: Stefan Wahren: "Re: [PATCH] staging: vchiq: Avoid mixing bulk_userdata kernel and userspace pointer"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

In vchiq_dev.c, there are two places where the __user bulk_userdata
pointer to set to a kernel-space pointer which then gives relevant
Sparse warnings as below:

vchiq_dev.c:328:26: warning: incorrect type in assignment (different address spaces)
vchiq_dev.c:328:26: expected void *[assigned] userdata
vchiq_dev.c:328:26: got void [noderef] __user *userdata
vchiq_dev.c:543:47: warning: incorrect type in assignment (different address spaces)
vchiq_dev.c:543:47: expected void [noderef] __user *[addressable] [assigned] bulk_userdata
vchiq_dev.c:543:47: got void *bulk_userdata

This is solved by adding additional functional argument to track the
userspace bulk_userdata separately and passing it accordingly to
completion handlers.

This patch is inspired by commit
1c954540c0eb ("staging: vchiq: avoid mixing kernel and user pointers").

There are no Sparse warnings left to be fixed in vc04_services,
hence drop the relevant TODO entry as well.

Signed-off-by: Umang Jain <umang.jain@xxxxxxxxxxxxxxxx>
---
.../bcm2835-audio/bcm2835-vchiq.c | 3 ++-
.../include/linux/raspberrypi/vchiq.h | 7 +++--
drivers/staging/vc04_services/interface/TODO | 4 ---
.../interface/vchiq_arm/vchiq_arm.c | 26 +++++++++++--------
.../interface/vchiq_arm/vchiq_arm.h | 3 ++-
.../interface/vchiq_arm/vchiq_core.c | 21 ++++++++-------
.../interface/vchiq_arm/vchiq_core.h | 5 ++--
.../interface/vchiq_arm/vchiq_dev.c | 10 ++-----
.../vc04_services/vchiq-mmal/mmal-vchiq.c | 2 +-
9 files changed, 42 insertions(+), 39 deletions(-)

diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
index 133ed15f3dbc..c44f3d5cca70 100644
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
@@ -96,7 +96,8 @@ static int bcm2835_audio_send_simple(struct bcm2835_audio_instance *instance,
static int audio_vchi_callback(struct vchiq_instance *vchiq_instance,
enum vchiq_reason reason,
struct vchiq_header *header,
- unsigned int handle, void *userdata)
+ unsigned int handle, void *userdata,
+ void __user *uuserdata)
{
struct bcm2835_audio_instance *instance = vchiq_get_service_userdata(vchiq_instance,
handle);
diff --git a/drivers/staging/vc04_services/include/linux/raspberrypi/vchiq.h b/drivers/staging/vc04_services/include/linux/raspberrypi/vchiq.h
index 6c40d8c1dde6..c777952dd9d9 100644
--- a/drivers/staging/vc04_services/include/linux/raspberrypi/vchiq.h
+++ b/drivers/staging/vc04_services/include/linux/raspberrypi/vchiq.h
@@ -56,7 +56,8 @@ struct vchiq_service_base {
enum vchiq_reason reason,
struct vchiq_header *header,
unsigned int handle,
- void *bulk_userdata);
+ void *bulk_userdata,
+ void __user *ubulk_userdata);
void *userdata;
};

@@ -65,6 +66,7 @@ struct vchiq_completion_data_kernel {
struct vchiq_header *header;
void *service_userdata;
void *bulk_userdata;
+ void __user *ubulk_userdata;
};

struct vchiq_service_params_kernel {
@@ -73,7 +75,8 @@ struct vchiq_service_params_kernel {
enum vchiq_reason reason,
struct vchiq_header *header,
unsigned int handle,
- void *bulk_userdata);
+ void *bulk_userdata,
+ void __user *ubulk_userdata);
void *userdata;
short version; /* Increment for non-trivial changes */
short version_min; /* Update for incompatible changes */
diff --git a/drivers/staging/vc04_services/interface/TODO b/drivers/staging/vc04_services/interface/TODO
index dfb1ee49633f..2ae75362421b 100644
--- a/drivers/staging/vc04_services/interface/TODO
+++ b/drivers/staging/vc04_services/interface/TODO
@@ -27,10 +27,6 @@ The code follows the 80 characters limitation yet tends to go 3 or 4 levels of
indentation deep making it very unpleasant to read. This is specially relevant
in the character driver ioctl code and in the core thread functions.

-* Clean up Sparse warnings from __user annotations. See
-vchiq_irq_queue_bulk_tx_rx(). Ensure that the address of "&waiter->bulk_waiter"
-is never disclosed to userspace.
-
* Fix behavior of message handling

The polling behavior of vchiq_bulk_transmit(), vchiq_bulk_receive() and
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index c4d97dbf6ba8..fae939f35642 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -859,7 +859,7 @@ vchiq_bulk_transmit(struct vchiq_instance *instance, unsigned int handle, const
case VCHIQ_BULK_MODE_CALLBACK:
ret = vchiq_bulk_transfer(instance, handle,
(void *)data, NULL,
- size, userdata, mode,
+ size, userdata, NULL, mode,
VCHIQ_BULK_TRANSMIT);
break;
case VCHIQ_BULK_MODE_BLOCKING:
@@ -896,7 +896,7 @@ int vchiq_bulk_receive(struct vchiq_instance *instance, unsigned int handle,
case VCHIQ_BULK_MODE_NOCALLBACK:
case VCHIQ_BULK_MODE_CALLBACK:
ret = vchiq_bulk_transfer(instance, handle, data, NULL,
- size, userdata,
+ size, userdata, NULL,
mode, VCHIQ_BULK_RECEIVE);
break;
case VCHIQ_BULK_MODE_BLOCKING:
@@ -969,7 +969,7 @@ vchiq_blocking_bulk_transfer(struct vchiq_instance *instance, unsigned int handl
}

ret = vchiq_bulk_transfer(instance, handle, data, NULL, size,
- &waiter->bulk_waiter,
+ &waiter->bulk_waiter, NULL,
VCHIQ_BULK_MODE_BLOCKING, dir);
if ((ret != -EAGAIN) || fatal_signal_pending(current) || !waiter->bulk_waiter.bulk) {
struct vchiq_bulk *bulk = waiter->bulk_waiter.bulk;
@@ -996,7 +996,7 @@ vchiq_blocking_bulk_transfer(struct vchiq_instance *instance, unsigned int handl
static int
add_completion(struct vchiq_instance *instance, enum vchiq_reason reason,
struct vchiq_header *header, struct user_service *user_service,
- void *bulk_userdata)
+ void *bulk_userdata, void __user *ubulk_userdata)
{
struct vchiq_completion_data_kernel *completion;
struct vchiq_drv_mgmt *mgmt = dev_get_drvdata(instance->state->dev);
@@ -1027,6 +1027,7 @@ add_completion(struct vchiq_instance *instance, enum vchiq_reason reason,
/* N.B. service_userdata is updated while processing AWAIT_COMPLETION */
completion->service_userdata = user_service->service;
completion->bulk_userdata = bulk_userdata;
+ completion->ubulk_userdata = ubulk_userdata;

if (reason == VCHIQ_SERVICE_CLOSED) {
/*
@@ -1058,7 +1059,8 @@ add_completion(struct vchiq_instance *instance, enum vchiq_reason reason,
static int
service_single_message(struct vchiq_instance *instance,
enum vchiq_reason reason,
- struct vchiq_service *service, void *bulk_userdata)
+ struct vchiq_service *service,
+ void *bulk_userdata, void __user *ubulk_userdata)
{
struct user_service *user_service;

@@ -1076,7 +1078,7 @@ service_single_message(struct vchiq_instance *instance,
dev_dbg(instance->state->dev,
"arm: Inserting extra MESSAGE_AVAILABLE\n");
ret = add_completion(instance, reason, NULL, user_service,
- bulk_userdata);
+ bulk_userdata, ubulk_userdata);
if (ret)
return ret;
}
@@ -1094,7 +1096,8 @@ service_single_message(struct vchiq_instance *instance,

int
service_callback(struct vchiq_instance *instance, enum vchiq_reason reason,
- struct vchiq_header *header, unsigned int handle, void *bulk_userdata)
+ struct vchiq_header *header, unsigned int handle,
+ void *bulk_userdata, void __user *ubulk_userdata)
{
/*
* How do we ensure the callback goes to the right client?
@@ -1147,8 +1150,8 @@ service_callback(struct vchiq_instance *instance, enum vchiq_reason reason,
DEBUG_TRACE(SERVICE_CALLBACK_LINE);
DEBUG_COUNT(MSG_QUEUE_FULL_COUNT);

- ret = service_single_message(instance, reason,
- service, bulk_userdata);
+ ret = service_single_message(instance, reason, service,
+ bulk_userdata, ubulk_userdata);
if (ret) {
DEBUG_TRACE(SERVICE_CALLBACK_LINE);
vchiq_service_put(service);
@@ -1186,7 +1189,7 @@ service_callback(struct vchiq_instance *instance, enum vchiq_reason reason,
return 0;

return add_completion(instance, reason, header, user_service,
- bulk_userdata);
+ bulk_userdata, ubulk_userdata);
}

void vchiq_dump_platform_instances(struct vchiq_state *state, struct seq_file *f)
@@ -1273,7 +1276,8 @@ static int
vchiq_keepalive_vchiq_callback(struct vchiq_instance *instance,
enum vchiq_reason reason,
struct vchiq_header *header,
- unsigned int service_user, void *bulk_user)
+ unsigned int service_user,
+ void *bulk_userdata, void __user *ubulk_userdata)
{
dev_err(instance->state->dev, "suspend: %s: callback reason %d\n",
__func__, reason);
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.h b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.h
index b402aac333d9..43c73e986779 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.h
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.h
@@ -155,7 +155,8 @@ static inline int vchiq_register_chrdev(struct device *parent) { return 0; }

extern int
service_callback(struct vchiq_instance *vchiq_instance, enum vchiq_reason reason,
- struct vchiq_header *header, unsigned int handle, void *bulk_userdata);
+ struct vchiq_header *header, unsigned int handle,
+ void *bulk_userdata, void __user *ubulk_userdata);

extern void
free_bulk_waiter(struct vchiq_instance *instance);
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
index 50af04b217f4..b24a27a46074 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
@@ -449,7 +449,8 @@ mark_service_closing(struct vchiq_service *service)

static inline int
make_service_callback(struct vchiq_service *service, enum vchiq_reason reason,
- struct vchiq_header *header, void *bulk_userdata)
+ struct vchiq_header *header,
+ void *bulk_userdata, void __user *ubulk_userdata)
{
int status;

@@ -457,7 +458,7 @@ make_service_callback(struct vchiq_service *service, enum vchiq_reason reason,
service->state->id, service->localport, reason_names[reason],
header, bulk_userdata);
status = service->base.callback(service->instance, reason, header, service->handle,
- bulk_userdata);
+ bulk_userdata, ubulk_userdata);
if (status && (status != -EAGAIN)) {
dev_warn(service->state->dev,
"core: %d: ignoring ERROR from callback to service %x\n",
@@ -1339,7 +1340,7 @@ notify_bulks(struct vchiq_service *service, struct vchiq_bulk_queue *queue,
enum vchiq_reason reason =
get_bulk_reason(bulk);
status = make_service_callback(service, reason, NULL,
- bulk->userdata);
+ bulk->userdata, bulk->uuserdata);
if (status == -EAGAIN)
break;
}
@@ -1689,7 +1690,7 @@ parse_message(struct vchiq_state *state, struct vchiq_header *header)
claim_slot(state->rx_info);
DEBUG_TRACE(PARSE_LINE);
if (make_service_callback(service, VCHIQ_MESSAGE_AVAILABLE, header,
- NULL) == -EAGAIN) {
+ NULL, NULL) == -EAGAIN) {
DEBUG_TRACE(PARSE_LINE);
goto bail_not_ready;
}
@@ -2072,7 +2073,7 @@ sync_func(void *v)
if ((service->remoteport == remoteport) &&
(service->srvstate == VCHIQ_SRVSTATE_OPENSYNC)) {
if (make_service_callback(service, VCHIQ_MESSAGE_AVAILABLE, header,
- NULL) == -EAGAIN)
+ NULL, NULL) == -EAGAIN)
dev_err(state->dev,
"sync: error: synchronous callback to service %d returns -EAGAIN\n",
localport);
@@ -2624,7 +2625,7 @@ close_service_complete(struct vchiq_service *service, int failstate)
return -EINVAL;
}

- status = make_service_callback(service, VCHIQ_SERVICE_CLOSED, NULL, NULL);
+ status = make_service_callback(service, VCHIQ_SERVICE_CLOSED, NULL, NULL, NULL);

if (status != -EAGAIN) {
int uc = service->service_use_count;
@@ -2987,7 +2988,8 @@ vchiq_remove_service(struct vchiq_instance *instance, unsigned int handle)
* structure.
*/
int vchiq_bulk_transfer(struct vchiq_instance *instance, unsigned int handle,
- void *offset, void __user *uoffset, int size, void *userdata,
+ void *offset, void __user *uoffset, int size,
+ void *userdata, void __user *uuserdata,
enum vchiq_bulk_mode mode, enum vchiq_bulk_dir dir)
{
struct vchiq_service *service = find_service_by_handle(instance, handle);
@@ -3062,6 +3064,7 @@ int vchiq_bulk_transfer(struct vchiq_instance *instance, unsigned int handle,
bulk->mode = mode;
bulk->dir = dir;
bulk->userdata = userdata;
+ bulk->uuserdata = uuserdata;
bulk->size = size;
bulk->actual = VCHIQ_BULK_ACTUAL_ABORTED;

@@ -3074,9 +3077,9 @@ int vchiq_bulk_transfer(struct vchiq_instance *instance, unsigned int handle,
*/
wmb();

- dev_dbg(state->dev, "core: %d: bt (%d->%d) %cx %x@%pad %pK\n",
+ dev_dbg(state->dev, "core: %d: bt (%d->%d) %cx %x@%pad %pK %p\n",
state->id, service->localport, service->remoteport,
- dir_char, size, &bulk->data, userdata);
+ dir_char, size, &bulk->data, userdata, uuserdata);

/*
* The slot mutex must be held when the service is being closed, so
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h
index 77cc4d7ac077..6d915aeeae7f 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h
@@ -114,6 +114,7 @@ struct vchiq_bulk {
short mode;
short dir;
void *userdata;
+ void __user *uuserdata;
dma_addr_t data;
int size;
void *remote_data;
@@ -472,8 +473,8 @@ remote_event_pollall(struct vchiq_state *state);

extern int
vchiq_bulk_transfer(struct vchiq_instance *instance, unsigned int handle, void *offset,
- void __user *uoffset, int size, void *userdata, enum vchiq_bulk_mode mode,
- enum vchiq_bulk_dir dir);
+ void __user *uoffset, int size, void *userdata, void __user *uuserdata,
+ enum vchiq_bulk_mode mode, enum vchiq_bulk_dir dir);

extern void
vchiq_dump_state(struct seq_file *f, struct vchiq_state *state);
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c
index 9cd2a64dce5e..3bb45342e89e 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c
@@ -324,12 +324,10 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_instance *instance,
dev_dbg(service->state->dev, "arm: found bulk_waiter %pK for pid %d\n",
waiter, current->pid);
userdata = &waiter->bulk_waiter;
- } else {
- userdata = args->userdata;
}

status = vchiq_bulk_transfer(instance, args->handle, NULL, args->data, args->size,
- userdata, args->mode, dir);
+ userdata, args->userdata, args->mode, dir);

if (!waiter) {
ret = 0;
@@ -536,11 +534,7 @@ static int vchiq_ioc_await_completion(struct vchiq_instance *instance,
!instance->use_close_delivered)
vchiq_service_put(service);

- /*
- * FIXME: address space mismatch, does bulk_userdata
- * actually point to user or kernel memory?
- */
- user_completion.bulk_userdata = completion->bulk_userdata;
+ user_completion.bulk_userdata = completion->ubulk_userdata;

if (vchiq_put_completion(args->buf, &user_completion, ret)) {
if (ret == 0)
diff --git a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
index 67489c334f7b..24777e570ad5 100644
--- a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
+++ b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
@@ -551,7 +551,7 @@ static void bulk_abort_cb(struct vchiq_mmal_instance *instance,
/* incoming event service callback */
static int mmal_service_callback(struct vchiq_instance *vchiq_instance,
enum vchiq_reason reason, struct vchiq_header *header,
- unsigned int handle, void *bulk_ctx)
+ unsigned int handle, void *bulk_ctx, void __user *bulk_uctx)
{
struct vchiq_mmal_instance *instance = vchiq_get_service_userdata(vchiq_instance, handle);
u32 msg_len;
--
2.45.0

Next message: Keith Busch: "Re: [PATCH] nvme-pci: add missing condition check for existence of mapped data"
Previous message: tip-bot2 for Thomas Gleixner: " [tip: timers/core] selftests/timers/posix_timers: Simplify error handling"
Next in thread: Stefan Wahren: "Re: [PATCH] staging: vchiq: Avoid mixing bulk_userdata kernel and userspace pointer"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]