linux/drivers/bluetooth/hci_ll.c
Sebastian Reichel f2edd9f67b Bluetooth: hci_ll: Fix NULL pointer deref on FW upload failure
Avoid NULL pointer dereference occurring due to freeing
skb containing an error pointer. It can easily be triggered
by using the driver with broken uart (i.e. due to misconfigured
pinmuxing).

Fixes: 371805522f ("bluetooth: hci_uart: add LL protocol serdev driver support")
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2017-04-22 10:28:40 +02:00

787 lines
18 KiB
C

/*
* Texas Instruments' Bluetooth HCILL UART protocol
*
* HCILL (HCI Low Level) is a Texas Instruments' power management
* protocol extension to H4.
*
* Copyright (C) 2007 Texas Instruments, Inc.
*
* Written by Ohad Ben-Cohen <ohad@bencohen.org>
*
* Acknowledgements:
* This file is based on hci_h4.c, which was written
* by Maxim Krasnyansky and Marcel Holtmann.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/firmware.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/signal.h>
#include <linux/ioctl.h>
#include <linux/of.h>
#include <linux/serdev.h>
#include <linux/skbuff.h>
#include <linux/ti_wilink_st.h>
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <linux/gpio/consumer.h>
#include "hci_uart.h"
/* HCILL commands */
#define HCILL_GO_TO_SLEEP_IND 0x30
#define HCILL_GO_TO_SLEEP_ACK 0x31
#define HCILL_WAKE_UP_IND 0x32
#define HCILL_WAKE_UP_ACK 0x33
/* HCILL receiver States */
#define HCILL_W4_PACKET_TYPE 0
#define HCILL_W4_EVENT_HDR 1
#define HCILL_W4_ACL_HDR 2
#define HCILL_W4_SCO_HDR 3
#define HCILL_W4_DATA 4
/* HCILL states */
enum hcill_states_e {
HCILL_ASLEEP,
HCILL_ASLEEP_TO_AWAKE,
HCILL_AWAKE,
HCILL_AWAKE_TO_ASLEEP
};
struct hcill_cmd {
u8 cmd;
} __packed;
struct ll_device {
struct hci_uart hu;
struct serdev_device *serdev;
struct gpio_desc *enable_gpio;
};
struct ll_struct {
unsigned long rx_state;
unsigned long rx_count;
struct sk_buff *rx_skb;
struct sk_buff_head txq;
spinlock_t hcill_lock; /* HCILL state lock */
unsigned long hcill_state; /* HCILL power state */
struct sk_buff_head tx_wait_q; /* HCILL wait queue */
};
/*
* Builds and sends an HCILL command packet.
* These are very simple packets with only 1 cmd byte
*/
static int send_hcill_cmd(u8 cmd, struct hci_uart *hu)
{
int err = 0;
struct sk_buff *skb = NULL;
struct ll_struct *ll = hu->priv;
struct hcill_cmd *hcill_packet;
BT_DBG("hu %p cmd 0x%x", hu, cmd);
/* allocate packet */
skb = bt_skb_alloc(1, GFP_ATOMIC);
if (!skb) {
BT_ERR("cannot allocate memory for HCILL packet");
err = -ENOMEM;
goto out;
}
/* prepare packet */
hcill_packet = (struct hcill_cmd *) skb_put(skb, 1);
hcill_packet->cmd = cmd;
/* send packet */
skb_queue_tail(&ll->txq, skb);
out:
return err;
}
/* Initialize protocol */
static int ll_open(struct hci_uart *hu)
{
struct ll_struct *ll;
BT_DBG("hu %p", hu);
ll = kzalloc(sizeof(*ll), GFP_KERNEL);
if (!ll)
return -ENOMEM;
skb_queue_head_init(&ll->txq);
skb_queue_head_init(&ll->tx_wait_q);
spin_lock_init(&ll->hcill_lock);
ll->hcill_state = HCILL_AWAKE;
hu->priv = ll;
if (hu->serdev)
serdev_device_open(hu->serdev);
return 0;
}
/* Flush protocol data */
static int ll_flush(struct hci_uart *hu)
{
struct ll_struct *ll = hu->priv;
BT_DBG("hu %p", hu);
skb_queue_purge(&ll->tx_wait_q);
skb_queue_purge(&ll->txq);
return 0;
}
/* Close protocol */
static int ll_close(struct hci_uart *hu)
{
struct ll_struct *ll = hu->priv;
BT_DBG("hu %p", hu);
skb_queue_purge(&ll->tx_wait_q);
skb_queue_purge(&ll->txq);
kfree_skb(ll->rx_skb);
if (hu->serdev) {
struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
gpiod_set_value_cansleep(lldev->enable_gpio, 0);
serdev_device_close(hu->serdev);
}
hu->priv = NULL;
kfree(ll);
return 0;
}
/*
* internal function, which does common work of the device wake up process:
* 1. places all pending packets (waiting in tx_wait_q list) in txq list.
* 2. changes internal state to HCILL_AWAKE.
* Note: assumes that hcill_lock spinlock is taken,
* shouldn't be called otherwise!
*/
static void __ll_do_awake(struct ll_struct *ll)
{
struct sk_buff *skb = NULL;
while ((skb = skb_dequeue(&ll->tx_wait_q)))
skb_queue_tail(&ll->txq, skb);
ll->hcill_state = HCILL_AWAKE;
}
/*
* Called upon a wake-up-indication from the device
*/
static void ll_device_want_to_wakeup(struct hci_uart *hu)
{
unsigned long flags;
struct ll_struct *ll = hu->priv;
BT_DBG("hu %p", hu);
/* lock hcill state */
spin_lock_irqsave(&ll->hcill_lock, flags);
switch (ll->hcill_state) {
case HCILL_ASLEEP_TO_AWAKE:
/*
* This state means that both the host and the BRF chip
* have simultaneously sent a wake-up-indication packet.
* Traditionally, in this case, receiving a wake-up-indication
* was enough and an additional wake-up-ack wasn't needed.
* This has changed with the BRF6350, which does require an
* explicit wake-up-ack. Other BRF versions, which do not
* require an explicit ack here, do accept it, thus it is
* perfectly safe to always send one.
*/
BT_DBG("dual wake-up-indication");
/* deliberate fall-through - do not add break */
case HCILL_ASLEEP:
/* acknowledge device wake up */
if (send_hcill_cmd(HCILL_WAKE_UP_ACK, hu) < 0) {
BT_ERR("cannot acknowledge device wake up");
goto out;
}
break;
default:
/* any other state is illegal */
BT_ERR("received HCILL_WAKE_UP_IND in state %ld", ll->hcill_state);
break;
}
/* send pending packets and change state to HCILL_AWAKE */
__ll_do_awake(ll);
out:
spin_unlock_irqrestore(&ll->hcill_lock, flags);
/* actually send the packets */
hci_uart_tx_wakeup(hu);
}
/*
* Called upon a sleep-indication from the device
*/
static void ll_device_want_to_sleep(struct hci_uart *hu)
{
unsigned long flags;
struct ll_struct *ll = hu->priv;
BT_DBG("hu %p", hu);
/* lock hcill state */
spin_lock_irqsave(&ll->hcill_lock, flags);
/* sanity check */
if (ll->hcill_state != HCILL_AWAKE)
BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld", ll->hcill_state);
/* acknowledge device sleep */
if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK, hu) < 0) {
BT_ERR("cannot acknowledge device sleep");
goto out;
}
/* update state */
ll->hcill_state = HCILL_ASLEEP;
out:
spin_unlock_irqrestore(&ll->hcill_lock, flags);
/* actually send the sleep ack packet */
hci_uart_tx_wakeup(hu);
}
/*
* Called upon wake-up-acknowledgement from the device
*/
static void ll_device_woke_up(struct hci_uart *hu)
{
unsigned long flags;
struct ll_struct *ll = hu->priv;
BT_DBG("hu %p", hu);
/* lock hcill state */
spin_lock_irqsave(&ll->hcill_lock, flags);
/* sanity check */
if (ll->hcill_state != HCILL_ASLEEP_TO_AWAKE)
BT_ERR("received HCILL_WAKE_UP_ACK in state %ld", ll->hcill_state);
/* send pending packets and change state to HCILL_AWAKE */
__ll_do_awake(ll);
spin_unlock_irqrestore(&ll->hcill_lock, flags);
/* actually send the packets */
hci_uart_tx_wakeup(hu);
}
/* Enqueue frame for transmittion (padding, crc, etc) */
/* may be called from two simultaneous tasklets */
static int ll_enqueue(struct hci_uart *hu, struct sk_buff *skb)
{
unsigned long flags = 0;
struct ll_struct *ll = hu->priv;
BT_DBG("hu %p skb %p", hu, skb);
/* Prepend skb with frame type */
memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
/* lock hcill state */
spin_lock_irqsave(&ll->hcill_lock, flags);
/* act according to current state */
switch (ll->hcill_state) {
case HCILL_AWAKE:
BT_DBG("device awake, sending normally");
skb_queue_tail(&ll->txq, skb);
break;
case HCILL_ASLEEP:
BT_DBG("device asleep, waking up and queueing packet");
/* save packet for later */
skb_queue_tail(&ll->tx_wait_q, skb);
/* awake device */
if (send_hcill_cmd(HCILL_WAKE_UP_IND, hu) < 0) {
BT_ERR("cannot wake up device");
break;
}
ll->hcill_state = HCILL_ASLEEP_TO_AWAKE;
break;
case HCILL_ASLEEP_TO_AWAKE:
BT_DBG("device waking up, queueing packet");
/* transient state; just keep packet for later */
skb_queue_tail(&ll->tx_wait_q, skb);
break;
default:
BT_ERR("illegal hcill state: %ld (losing packet)", ll->hcill_state);
kfree_skb(skb);
break;
}
spin_unlock_irqrestore(&ll->hcill_lock, flags);
return 0;
}
static inline int ll_check_data_len(struct hci_dev *hdev, struct ll_struct *ll, int len)
{
int room = skb_tailroom(ll->rx_skb);
BT_DBG("len %d room %d", len, room);
if (!len) {
hci_recv_frame(hdev, ll->rx_skb);
} else if (len > room) {
BT_ERR("Data length is too large");
kfree_skb(ll->rx_skb);
} else {
ll->rx_state = HCILL_W4_DATA;
ll->rx_count = len;
return len;
}
ll->rx_state = HCILL_W4_PACKET_TYPE;
ll->rx_skb = NULL;
ll->rx_count = 0;
return 0;
}
/* Recv data */
static int ll_recv(struct hci_uart *hu, const void *data, int count)
{
struct ll_struct *ll = hu->priv;
const char *ptr;
struct hci_event_hdr *eh;
struct hci_acl_hdr *ah;
struct hci_sco_hdr *sh;
int len, type, dlen;
BT_DBG("hu %p count %d rx_state %ld rx_count %ld", hu, count, ll->rx_state, ll->rx_count);
ptr = data;
while (count) {
if (ll->rx_count) {
len = min_t(unsigned int, ll->rx_count, count);
memcpy(skb_put(ll->rx_skb, len), ptr, len);
ll->rx_count -= len; count -= len; ptr += len;
if (ll->rx_count)
continue;
switch (ll->rx_state) {
case HCILL_W4_DATA:
BT_DBG("Complete data");
hci_recv_frame(hu->hdev, ll->rx_skb);
ll->rx_state = HCILL_W4_PACKET_TYPE;
ll->rx_skb = NULL;
continue;
case HCILL_W4_EVENT_HDR:
eh = hci_event_hdr(ll->rx_skb);
BT_DBG("Event header: evt 0x%2.2x plen %d", eh->evt, eh->plen);
ll_check_data_len(hu->hdev, ll, eh->plen);
continue;
case HCILL_W4_ACL_HDR:
ah = hci_acl_hdr(ll->rx_skb);
dlen = __le16_to_cpu(ah->dlen);
BT_DBG("ACL header: dlen %d", dlen);
ll_check_data_len(hu->hdev, ll, dlen);
continue;
case HCILL_W4_SCO_HDR:
sh = hci_sco_hdr(ll->rx_skb);
BT_DBG("SCO header: dlen %d", sh->dlen);
ll_check_data_len(hu->hdev, ll, sh->dlen);
continue;
}
}
/* HCILL_W4_PACKET_TYPE */
switch (*ptr) {
case HCI_EVENT_PKT:
BT_DBG("Event packet");
ll->rx_state = HCILL_W4_EVENT_HDR;
ll->rx_count = HCI_EVENT_HDR_SIZE;
type = HCI_EVENT_PKT;
break;
case HCI_ACLDATA_PKT:
BT_DBG("ACL packet");
ll->rx_state = HCILL_W4_ACL_HDR;
ll->rx_count = HCI_ACL_HDR_SIZE;
type = HCI_ACLDATA_PKT;
break;
case HCI_SCODATA_PKT:
BT_DBG("SCO packet");
ll->rx_state = HCILL_W4_SCO_HDR;
ll->rx_count = HCI_SCO_HDR_SIZE;
type = HCI_SCODATA_PKT;
break;
/* HCILL signals */
case HCILL_GO_TO_SLEEP_IND:
BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
ll_device_want_to_sleep(hu);
ptr++; count--;
continue;
case HCILL_GO_TO_SLEEP_ACK:
/* shouldn't happen */
BT_ERR("received HCILL_GO_TO_SLEEP_ACK (in state %ld)", ll->hcill_state);
ptr++; count--;
continue;
case HCILL_WAKE_UP_IND:
BT_DBG("HCILL_WAKE_UP_IND packet");
ll_device_want_to_wakeup(hu);
ptr++; count--;
continue;
case HCILL_WAKE_UP_ACK:
BT_DBG("HCILL_WAKE_UP_ACK packet");
ll_device_woke_up(hu);
ptr++; count--;
continue;
default:
BT_ERR("Unknown HCI packet type %2.2x", (__u8)*ptr);
hu->hdev->stat.err_rx++;
ptr++; count--;
continue;
}
ptr++; count--;
/* Allocate packet */
ll->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
if (!ll->rx_skb) {
BT_ERR("Can't allocate mem for new packet");
ll->rx_state = HCILL_W4_PACKET_TYPE;
ll->rx_count = 0;
return -ENOMEM;
}
hci_skb_pkt_type(ll->rx_skb) = type;
}
return count;
}
static struct sk_buff *ll_dequeue(struct hci_uart *hu)
{
struct ll_struct *ll = hu->priv;
return skb_dequeue(&ll->txq);
}
#if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
static int read_local_version(struct hci_dev *hdev)
{
int err = 0;
unsigned short version = 0;
struct sk_buff *skb;
struct hci_rp_read_local_version *ver;
skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL, HCI_INIT_TIMEOUT);
if (IS_ERR(skb)) {
bt_dev_err(hdev, "Reading TI version information failed (%ld)",
PTR_ERR(skb));
return PTR_ERR(skb);
}
if (skb->len != sizeof(*ver)) {
err = -EILSEQ;
goto out;
}
ver = (struct hci_rp_read_local_version *)skb->data;
if (le16_to_cpu(ver->manufacturer) != 13) {
err = -ENODEV;
goto out;
}
version = le16_to_cpu(ver->lmp_subver);
out:
if (err) bt_dev_err(hdev, "Failed to read TI version info: %d", err);
kfree_skb(skb);
return err ? err : version;
}
/**
* download_firmware -
* internal function which parses through the .bts firmware
* script file intreprets SEND, DELAY actions only as of now
*/
static int download_firmware(struct ll_device *lldev)
{
unsigned short chip, min_ver, maj_ver;
int version, err, len;
unsigned char *ptr, *action_ptr;
unsigned char bts_scr_name[40]; /* 40 char long bts scr name? */
const struct firmware *fw;
struct sk_buff *skb;
struct hci_command *cmd;
version = read_local_version(lldev->hu.hdev);
if (version < 0)
return version;
chip = (version & 0x7C00) >> 10;
min_ver = (version & 0x007F);
maj_ver = (version & 0x0380) >> 7;
if (version & 0x8000)
maj_ver |= 0x0008;
snprintf(bts_scr_name, sizeof(bts_scr_name),
"ti-connectivity/TIInit_%d.%d.%d.bts",
chip, maj_ver, min_ver);
err = request_firmware(&fw, bts_scr_name, &lldev->serdev->dev);
if (err || !fw->data || !fw->size) {
bt_dev_err(lldev->hu.hdev, "request_firmware failed(errno %d) for %s",
err, bts_scr_name);
return -EINVAL;
}
ptr = (void *)fw->data;
len = fw->size;
/* bts_header to remove out magic number and
* version
*/
ptr += sizeof(struct bts_header);
len -= sizeof(struct bts_header);
while (len > 0 && ptr) {
bt_dev_dbg(lldev->hu.hdev, " action size %d, type %d ",
((struct bts_action *)ptr)->size,
((struct bts_action *)ptr)->type);
action_ptr = &(((struct bts_action *)ptr)->data[0]);
switch (((struct bts_action *)ptr)->type) {
case ACTION_SEND_COMMAND: /* action send */
bt_dev_dbg(lldev->hu.hdev, "S");
cmd = (struct hci_command *)action_ptr;
if (cmd->opcode == 0xff36) {
/* ignore remote change
* baud rate HCI VS command */
bt_dev_warn(lldev->hu.hdev, "change remote baud rate command in firmware");
break;
}
if (cmd->prefix != 1)
bt_dev_dbg(lldev->hu.hdev, "command type %d\n", cmd->prefix);
skb = __hci_cmd_sync(lldev->hu.hdev, cmd->opcode, cmd->plen, &cmd->speed, HCI_INIT_TIMEOUT);
if (IS_ERR(skb)) {
bt_dev_err(lldev->hu.hdev, "send command failed\n");
goto out_rel_fw;
}
kfree_skb(skb);
break;
case ACTION_WAIT_EVENT: /* wait */
/* no need to wait as command was synchronous */
bt_dev_dbg(lldev->hu.hdev, "W");
break;
case ACTION_DELAY: /* sleep */
bt_dev_info(lldev->hu.hdev, "sleep command in scr");
mdelay(((struct bts_action_delay *)action_ptr)->msec);
break;
}
len -= (sizeof(struct bts_action) +
((struct bts_action *)ptr)->size);
ptr += sizeof(struct bts_action) +
((struct bts_action *)ptr)->size;
}
out_rel_fw:
/* fw download complete */
release_firmware(fw);
return err;
}
static int ll_setup(struct hci_uart *hu)
{
int err, retry = 3;
struct ll_device *lldev;
struct serdev_device *serdev = hu->serdev;
u32 speed;
if (!serdev)
return 0;
lldev = serdev_device_get_drvdata(serdev);
serdev_device_set_flow_control(serdev, true);
do {
/* Configure BT_EN to HIGH state */
gpiod_set_value_cansleep(lldev->enable_gpio, 0);
msleep(5);
gpiod_set_value_cansleep(lldev->enable_gpio, 1);
msleep(100);
err = download_firmware(lldev);
if (!err)
break;
/* Toggle BT_EN and retry */
bt_dev_err(hu->hdev, "download firmware failed, retrying...");
} while (retry--);
if (err)
return err;
/* Operational speed if any */
if (hu->oper_speed)
speed = hu->oper_speed;
else if (hu->proto->oper_speed)
speed = hu->proto->oper_speed;
else
speed = 0;
if (speed) {
struct sk_buff *skb = __hci_cmd_sync(hu->hdev, 0xff36, sizeof(speed), &speed, HCI_INIT_TIMEOUT);
if (!IS_ERR(skb)) {
kfree_skb(skb);
serdev_device_set_baudrate(serdev, speed);
}
}
return 0;
}
static const struct hci_uart_proto llp;
static int hci_ti_probe(struct serdev_device *serdev)
{
struct hci_uart *hu;
struct ll_device *lldev;
u32 max_speed = 3000000;
lldev = devm_kzalloc(&serdev->dev, sizeof(struct ll_device), GFP_KERNEL);
if (!lldev)
return -ENOMEM;
hu = &lldev->hu;
serdev_device_set_drvdata(serdev, lldev);
lldev->serdev = hu->serdev = serdev;
lldev->enable_gpio = devm_gpiod_get_optional(&serdev->dev, "enable", GPIOD_OUT_LOW);
if (IS_ERR(lldev->enable_gpio))
return PTR_ERR(lldev->enable_gpio);
of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
hci_uart_set_speeds(hu, 115200, max_speed);
return hci_uart_register_device(hu, &llp);
}
static void hci_ti_remove(struct serdev_device *serdev)
{
struct ll_device *lldev = serdev_device_get_drvdata(serdev);
struct hci_uart *hu = &lldev->hu;
struct hci_dev *hdev = hu->hdev;
cancel_work_sync(&hu->write_work);
hci_unregister_dev(hdev);
hci_free_dev(hdev);
hu->proto->close(hu);
}
static const struct of_device_id hci_ti_of_match[] = {
{ .compatible = "ti,wl1831-st" },
{ .compatible = "ti,wl1835-st" },
{ .compatible = "ti,wl1837-st" },
{},
};
MODULE_DEVICE_TABLE(of, hci_ti_of_match);
static struct serdev_device_driver hci_ti_drv = {
.driver = {
.name = "hci-ti",
.of_match_table = of_match_ptr(hci_ti_of_match),
},
.probe = hci_ti_probe,
.remove = hci_ti_remove,
};
#else
#define ll_setup NULL
#endif
static const struct hci_uart_proto llp = {
.id = HCI_UART_LL,
.name = "LL",
.setup = ll_setup,
.open = ll_open,
.close = ll_close,
.recv = ll_recv,
.enqueue = ll_enqueue,
.dequeue = ll_dequeue,
.flush = ll_flush,
};
int __init ll_init(void)
{
serdev_device_driver_register(&hci_ti_drv);
return hci_uart_register_proto(&llp);
}
int __exit ll_deinit(void)
{
serdev_device_driver_unregister(&hci_ti_drv);
return hci_uart_unregister_proto(&llp);
}