mwifiex: resolve races between async FW init (failure) and device removal

It's possible for the FW init sequence to fail, which will trigger a
device cleanup sequence in mwifiex_fw_dpc(). This sequence can race with
device suspend() or remove() (e.g., reboot or unbind), and can trigger
use-after-free issues. Currently, this driver attempts (poorly) to
synchronize remove() using a semaphore, but it doesn't protect some of
the critical sections properly. Particularly, we grab a pointer to the
adapter struct (card->adapter) without checking if it's being freed or
not. We later do a NULL check on the adapter, but that doesn't work if
the adapter was freed.

Also note that the PCIe interface driver doesn't ever set card->adapter
to NULL, so even if we get the synchronization right, we still might try
to redo the cleanup in ->remove(), even if the FW init failure sequence
already did it.

This patch replaces the static semaphore with a per-device completion
struct, and uses that completion to synchronize the remove() thread with
the mwifiex_fw_dpc(). A future patch will utilize this completion to
synchronize the suspend() thread as well.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
This commit is contained in:
Brian Norris 2016-11-18 19:30:26 +05:30 committed by Kalle Valo
parent 6712076883
commit 4a79aa17d5
8 changed files with 55 additions and 68 deletions

View File

@ -521,9 +521,9 @@ static void mwifiex_fw_dpc(const struct firmware *firmware, void *context)
struct mwifiex_private *priv;
struct mwifiex_adapter *adapter = context;
struct mwifiex_fw_image fw;
struct semaphore *sem = adapter->card_sem;
bool init_failed = false;
struct wireless_dev *wdev;
struct completion *fw_done = adapter->fw_done;
if (!firmware) {
mwifiex_dbg(adapter, ERROR,
@ -670,7 +670,8 @@ done:
}
if (init_failed)
mwifiex_free_adapter(adapter);
up(sem);
/* Tell all current and future waiters we're finished */
complete_all(fw_done);
return;
}
@ -1365,7 +1366,7 @@ static void mwifiex_main_work_queue(struct work_struct *work)
* code is extracted from mwifiex_remove_card()
*/
static int
mwifiex_shutdown_sw(struct mwifiex_adapter *adapter, struct semaphore *sem)
mwifiex_shutdown_sw(struct mwifiex_adapter *adapter)
{
struct mwifiex_private *priv;
int i;
@ -1373,8 +1374,9 @@ mwifiex_shutdown_sw(struct mwifiex_adapter *adapter, struct semaphore *sem)
if (!adapter)
goto exit_return;
if (down_interruptible(sem))
goto exit_sem_err;
wait_for_completion(adapter->fw_done);
/* Caller should ensure we aren't suspending while this happens */
reinit_completion(adapter->fw_done);
priv = mwifiex_get_priv(adapter, MWIFIEX_BSS_ROLE_ANY);
mwifiex_deauthenticate(priv, NULL);
@ -1431,8 +1433,6 @@ mwifiex_shutdown_sw(struct mwifiex_adapter *adapter, struct semaphore *sem)
rtnl_unlock();
}
up(sem);
exit_sem_err:
mwifiex_dbg(adapter, INFO, "%s, successful\n", __func__);
exit_return:
return 0;
@ -1442,21 +1442,18 @@ exit_return:
* code is extracted from mwifiex_add_card()
*/
static int
mwifiex_reinit_sw(struct mwifiex_adapter *adapter, struct semaphore *sem,
mwifiex_reinit_sw(struct mwifiex_adapter *adapter, struct completion *fw_done,
struct mwifiex_if_ops *if_ops, u8 iface_type)
{
char fw_name[32];
struct pcie_service_card *card = adapter->card;
if (down_interruptible(sem))
goto exit_sem_err;
mwifiex_init_lock_list(adapter);
if (adapter->if_ops.up_dev)
adapter->if_ops.up_dev(adapter);
adapter->iface_type = iface_type;
adapter->card_sem = sem;
adapter->fw_done = fw_done;
adapter->hw_status = MWIFIEX_HW_STATUS_INITIALIZING;
adapter->surprise_removed = false;
@ -1507,7 +1504,8 @@ mwifiex_reinit_sw(struct mwifiex_adapter *adapter, struct semaphore *sem,
}
strcpy(adapter->fw_name, fw_name);
mwifiex_dbg(adapter, INFO, "%s, successful\n", __func__);
up(sem);
complete_all(adapter->fw_done);
return 0;
err_init_fw:
@ -1527,8 +1525,7 @@ err_init_fw:
err_kmalloc:
mwifiex_terminate_workqueue(adapter);
adapter->surprise_removed = true;
up(sem);
exit_sem_err:
complete_all(adapter->fw_done);
mwifiex_dbg(adapter, INFO, "%s, error\n", __func__);
return -1;
@ -1543,12 +1540,12 @@ void mwifiex_do_flr(struct mwifiex_adapter *adapter, bool prepare)
struct mwifiex_if_ops if_ops;
if (!prepare) {
mwifiex_reinit_sw(adapter, adapter->card_sem, &if_ops,
mwifiex_reinit_sw(adapter, adapter->fw_done, &if_ops,
adapter->iface_type);
} else {
memcpy(&if_ops, &adapter->if_ops,
sizeof(struct mwifiex_if_ops));
mwifiex_shutdown_sw(adapter, adapter->card_sem);
mwifiex_shutdown_sw(adapter);
}
}
EXPORT_SYMBOL_GPL(mwifiex_do_flr);
@ -1618,15 +1615,12 @@ err_exit:
* - Add logical interfaces
*/
int
mwifiex_add_card(void *card, struct semaphore *sem,
mwifiex_add_card(void *card, struct completion *fw_done,
struct mwifiex_if_ops *if_ops, u8 iface_type,
struct device *dev)
{
struct mwifiex_adapter *adapter;
if (down_interruptible(sem))
goto exit_sem_err;
if (mwifiex_register(card, if_ops, (void **)&adapter)) {
pr_err("%s: software init failed\n", __func__);
goto err_init_sw;
@ -1636,7 +1630,7 @@ mwifiex_add_card(void *card, struct semaphore *sem,
mwifiex_probe_of(adapter);
adapter->iface_type = iface_type;
adapter->card_sem = sem;
adapter->fw_done = fw_done;
adapter->hw_status = MWIFIEX_HW_STATUS_INITIALIZING;
adapter->surprise_removed = false;
@ -1705,9 +1699,7 @@ err_kmalloc:
mwifiex_free_adapter(adapter);
err_init_sw:
up(sem);
exit_sem_err:
return -1;
}
EXPORT_SYMBOL_GPL(mwifiex_add_card);
@ -1723,14 +1715,11 @@ EXPORT_SYMBOL_GPL(mwifiex_add_card);
* - Unregister the device
* - Free the adapter structure
*/
int mwifiex_remove_card(struct mwifiex_adapter *adapter, struct semaphore *sem)
int mwifiex_remove_card(struct mwifiex_adapter *adapter)
{
struct mwifiex_private *priv = NULL;
int i;
if (down_trylock(sem))
goto exit_sem_err;
if (!adapter)
goto exit_remove;
@ -1800,8 +1789,6 @@ int mwifiex_remove_card(struct mwifiex_adapter *adapter, struct semaphore *sem)
mwifiex_free_adapter(adapter);
exit_remove:
up(sem);
exit_sem_err:
return 0;
}
EXPORT_SYMBOL_GPL(mwifiex_remove_card);

View File

@ -20,6 +20,7 @@
#ifndef _MWIFIEX_MAIN_H_
#define _MWIFIEX_MAIN_H_
#include <linux/completion.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
@ -985,7 +986,10 @@ struct mwifiex_adapter {
u32 usr_dot_11ac_mcs_support;
atomic_t pending_bridged_pkts;
struct semaphore *card_sem;
/* For synchronizing FW initialization with device lifecycle. */
struct completion *fw_done;
bool ext_scan;
u8 fw_api_ver;
u8 key_api_major_ver, key_api_minor_ver;
@ -1438,10 +1442,11 @@ static inline void mwifiex_enable_wake(struct mwifiex_adapter *adapter)
int mwifiex_init_shutdown_fw(struct mwifiex_private *priv,
u32 func_init_shutdown);
int mwifiex_add_card(void *card, struct semaphore *sem,
int mwifiex_add_card(void *card, struct completion *fw_done,
struct mwifiex_if_ops *if_ops, u8 iface_type,
struct device *dev);
int mwifiex_remove_card(struct mwifiex_adapter *, struct semaphore *);
int mwifiex_remove_card(struct mwifiex_adapter *adapter);
void mwifiex_get_version(struct mwifiex_adapter *adapter, char *version,
int maxlen);

View File

@ -35,8 +35,6 @@ static u8 user_rmmod;
static struct mwifiex_if_ops pcie_ops;
static struct semaphore add_remove_card_sem;
static const struct of_device_id mwifiex_pcie_of_match_table[] = {
{ .compatible = "pci11ab,2b42" },
{ .compatible = "pci1b4b,2b42" },
@ -212,6 +210,8 @@ static int mwifiex_pcie_probe(struct pci_dev *pdev,
if (!card)
return -ENOMEM;
init_completion(&card->fw_done);
card->dev = pdev;
if (ent->driver_data) {
@ -232,7 +232,7 @@ static int mwifiex_pcie_probe(struct pci_dev *pdev,
return ret;
}
if (mwifiex_add_card(card, &add_remove_card_sem, &pcie_ops,
if (mwifiex_add_card(card, &card->fw_done, &pcie_ops,
MWIFIEX_PCIE, &pdev->dev)) {
pr_err("%s failed\n", __func__);
return -1;
@ -254,6 +254,8 @@ static void mwifiex_pcie_remove(struct pci_dev *pdev)
if (!card)
return;
wait_for_completion(&card->fw_done);
adapter = card->adapter;
if (!adapter || !adapter->priv_num)
return;
@ -273,7 +275,7 @@ static void mwifiex_pcie_remove(struct pci_dev *pdev)
mwifiex_init_shutdown_fw(priv, MWIFIEX_FUNC_SHUTDOWN);
}
mwifiex_remove_card(card->adapter, &add_remove_card_sem);
mwifiex_remove_card(adapter);
}
static void mwifiex_pcie_shutdown(struct pci_dev *pdev)
@ -3175,8 +3177,7 @@ static struct mwifiex_if_ops pcie_ops = {
/*
* This function initializes the PCIE driver module.
*
* This initiates the semaphore and registers the device with
* PCIE bus.
* This registers the device with PCIE bus.
*/
static int mwifiex_pcie_init_module(void)
{
@ -3184,8 +3185,6 @@ static int mwifiex_pcie_init_module(void)
pr_debug("Marvell PCIe Driver\n");
sema_init(&add_remove_card_sem, 1);
/* Clear the flag in case user removes the card. */
user_rmmod = 0;
@ -3209,9 +3208,6 @@ static int mwifiex_pcie_init_module(void)
*/
static void mwifiex_pcie_cleanup_module(void)
{
if (!down_interruptible(&add_remove_card_sem))
up(&add_remove_card_sem);
/* Set the flag as user is removing this module. */
user_rmmod = 1;

View File

@ -22,6 +22,7 @@
#ifndef _MWIFIEX_PCIE_H
#define _MWIFIEX_PCIE_H
#include <linux/completion.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
@ -345,6 +346,7 @@ struct pcie_service_card {
struct pci_dev *dev;
struct mwifiex_adapter *adapter;
struct mwifiex_pcie_device pcie;
struct completion fw_done;
u8 txbd_flush;
u32 txbd_wrptr;

View File

@ -49,8 +49,6 @@ static u8 user_rmmod;
static struct mwifiex_if_ops sdio_ops;
static unsigned long iface_work_flags;
static struct semaphore add_remove_card_sem;
static struct memory_type_mapping generic_mem_type_map[] = {
{"DUMP", NULL, 0, 0xDD},
};
@ -115,6 +113,8 @@ mwifiex_sdio_probe(struct sdio_func *func, const struct sdio_device_id *id)
if (!card)
return -ENOMEM;
init_completion(&card->fw_done);
card->func = func;
card->device_id = id;
@ -154,7 +154,7 @@ mwifiex_sdio_probe(struct sdio_func *func, const struct sdio_device_id *id)
goto err_disable;
}
ret = mwifiex_add_card(card, &add_remove_card_sem, &sdio_ops,
ret = mwifiex_add_card(card, &card->fw_done, &sdio_ops,
MWIFIEX_SDIO, &func->dev);
if (ret) {
dev_err(&func->dev, "add card failed\n");
@ -235,6 +235,8 @@ mwifiex_sdio_remove(struct sdio_func *func)
if (!card)
return;
wait_for_completion(&card->fw_done);
adapter = card->adapter;
if (!adapter || !adapter->priv_num)
return;
@ -252,7 +254,7 @@ mwifiex_sdio_remove(struct sdio_func *func)
mwifiex_init_shutdown_fw(priv, MWIFIEX_FUNC_SHUTDOWN);
}
mwifiex_remove_card(card->adapter, &add_remove_card_sem);
mwifiex_remove_card(adapter);
}
/*
@ -2714,14 +2716,11 @@ static struct mwifiex_if_ops sdio_ops = {
/*
* This function initializes the SDIO driver.
*
* This initiates the semaphore and registers the device with
* SDIO bus.
* This registers the device with SDIO bus.
*/
static int
mwifiex_sdio_init_module(void)
{
sema_init(&add_remove_card_sem, 1);
/* Clear the flag in case user removes the card. */
user_rmmod = 0;
@ -2740,9 +2739,6 @@ mwifiex_sdio_init_module(void)
static void
mwifiex_sdio_cleanup_module(void)
{
if (!down_interruptible(&add_remove_card_sem))
up(&add_remove_card_sem);
/* Set the flag as user is removing this module. */
user_rmmod = 1;
cancel_work_sync(&sdio_work);

View File

@ -21,6 +21,7 @@
#define _MWIFIEX_SDIO_H
#include <linux/completion.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/sdio_ids.h>
#include <linux/mmc/sdio_func.h>
@ -238,6 +239,7 @@ struct sdio_mmc_card {
struct sdio_func *func;
struct mwifiex_adapter *adapter;
struct completion fw_done;
const char *firmware;
const struct mwifiex_sdio_card_reg *reg;
u8 max_ports;

View File

@ -24,7 +24,6 @@
static u8 user_rmmod;
static struct mwifiex_if_ops usb_ops;
static struct semaphore add_remove_card_sem;
static struct usb_device_id mwifiex_usb_table[] = {
/* 8766 */
@ -386,6 +385,8 @@ static int mwifiex_usb_probe(struct usb_interface *intf,
if (!card)
return -ENOMEM;
init_completion(&card->fw_done);
id_vendor = le16_to_cpu(udev->descriptor.idVendor);
id_product = le16_to_cpu(udev->descriptor.idProduct);
bcd_device = le16_to_cpu(udev->descriptor.bcdDevice);
@ -475,7 +476,7 @@ static int mwifiex_usb_probe(struct usb_interface *intf,
usb_set_intfdata(intf, card);
ret = mwifiex_add_card(card, &add_remove_card_sem, &usb_ops,
ret = mwifiex_add_card(card, &card->fw_done, &usb_ops,
MWIFIEX_USB, &card->udev->dev);
if (ret) {
pr_err("%s: mwifiex_add_card failed: %d\n", __func__, ret);
@ -601,13 +602,15 @@ static void mwifiex_usb_disconnect(struct usb_interface *intf)
struct usb_card_rec *card = usb_get_intfdata(intf);
struct mwifiex_adapter *adapter;
if (!card || !card->adapter) {
pr_err("%s: card or card->adapter is NULL\n", __func__);
if (!card) {
dev_err(&intf->dev, "%s: card is NULL\n", __func__);
return;
}
wait_for_completion(&card->fw_done);
adapter = card->adapter;
if (!adapter->priv_num)
if (!adapter || !adapter->priv_num)
return;
if (user_rmmod && !adapter->mfg_mode) {
@ -627,7 +630,7 @@ static void mwifiex_usb_disconnect(struct usb_interface *intf)
mwifiex_dbg(adapter, FATAL,
"%s: removing card\n", __func__);
mwifiex_remove_card(adapter, &add_remove_card_sem);
mwifiex_remove_card(adapter);
usb_put_dev(interface_to_usbdev(intf));
}
@ -1200,8 +1203,7 @@ static struct mwifiex_if_ops usb_ops = {
/* This function initializes the USB driver module.
*
* This initiates the semaphore and registers the device with
* USB bus.
* This registers the device with USB bus.
*/
static int mwifiex_usb_init_module(void)
{
@ -1209,8 +1211,6 @@ static int mwifiex_usb_init_module(void)
pr_debug("Marvell USB8797 Driver\n");
sema_init(&add_remove_card_sem, 1);
ret = usb_register(&mwifiex_usb_driver);
if (ret)
pr_err("Driver register failed!\n");
@ -1230,9 +1230,6 @@ static int mwifiex_usb_init_module(void)
*/
static void mwifiex_usb_cleanup_module(void)
{
if (!down_interruptible(&add_remove_card_sem))
up(&add_remove_card_sem);
/* set the flag as user is removing this module */
user_rmmod = 1;

View File

@ -20,6 +20,7 @@
#ifndef _MWIFIEX_USB_H
#define _MWIFIEX_USB_H
#include <linux/completion.h>
#include <linux/usb.h>
#define USB8XXX_VID 0x1286
@ -75,6 +76,7 @@ struct usb_card_rec {
struct mwifiex_adapter *adapter;
struct usb_device *udev;
struct usb_interface *intf;
struct completion fw_done;
u8 rx_cmd_ep;
struct urb_context rx_cmd;
atomic_t rx_cmd_urb_pending;