[PATCH 4.4 041/101] ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb

Greg Kroah-Hartman
2020-06-19T14:37:09Z

From: Qiujun Huang <hqjagain@gmail.com>

commit 2bbcaaee1fcbd83272e29f31e2bb7e70d8c49e05 upstream.

In ath9k_hif_usb_rx_cb interface number is assumed to be 0.
usb_ifnum_to_if(urb->dev, 0)
But it isn't always true.

The case reported by syzbot:
https://lore.kernel.org/linux-usb/000000000000666c9c05a1c05d12@google.com
usb 2-1: new high-speed USB device number 2 using dummy_hcd
usb 2-1: config 1 has an invalid interface number: 2 but max is 0
usb 2-1: config 1 has no interface number 0
usb 2-1: New USB device found, idVendor=0cf3, idProduct=9271, bcdDevice=
1.08
usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
general protection fault, probably for non-canonical address
0xdffffc0000000015: 0000 [#1] SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000a8-0x00000000000000af]
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc5-syzkaller #0

Call Trace
__usb_hcd_giveback_urb+0x29a/0x550 drivers/usb/core/hcd.c:1650
usb_hcd_giveback_urb+0x368/0x420 drivers/usb/core/hcd.c:1716
dummy_timer+0x1258/0x32ae drivers/usb/gadget/udc/dummy_hcd.c:1966
call_timer_fn+0x195/0x6f0 kernel/time/timer.c:1404
expire_timers kernel/time/timer.c:1449 [inline]
__run_timers kernel/time/timer.c:1773 [inline]
__run_timers kernel/time/timer.c:1740 [inline]
run_timer_softirq+0x5f9/0x1500 kernel/time/timer.c:1786
__do_softirq+0x21e/0x950 kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x178/0x1a0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:546 [inline]
smp_apic_timer_interrupt+0x141/0x540 arch/x86/kernel/apic/apic.c:1146
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829

Reported-and-tested-by: syzbot+40d5d2e8a4680952f042@syzkaller.appspotmail.com
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200404041838.10426-6-hqjagain@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/wireless/ath/ath9k/hif_usb.c | 48 +++++++++++++++++++++++--------
drivers/net/wireless/ath/ath9k/hif_usb.h | 5 +++
2 files changed, 42 insertions(+), 11 deletions(-)

--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -639,9 +639,9 @@ err:

static void ath9k_hif_usb_rx_cb(struct urb *urb)
{
- struct sk_buff *skb = (struct sk_buff *) urb->context;
- struct hif_device_usb *hif_dev =
- usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0));
+ struct rx_buf *rx_buf = (struct rx_buf *)urb->context;
+ struct hif_device_usb *hif_dev = rx_buf->hif_dev;
+ struct sk_buff *skb = rx_buf->skb;
int ret;

if (!skb)
@@ -681,14 +681,15 @@ resubmit:
return;
free:
kfree_skb(skb);
+ kfree(rx_buf);
}

static void ath9k_hif_usb_reg_in_cb(struct urb *urb)
{
- struct sk_buff *skb = (struct sk_buff *) urb->context;
+ struct rx_buf *rx_buf = (struct rx_buf *)urb->context;
+ struct hif_device_usb *hif_dev = rx_buf->hif_dev;
+ struct sk_buff *skb = rx_buf->skb;
struct sk_buff *nskb;
- struct hif_device_usb *hif_dev =
- usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0));
int ret;

if (!skb)
@@ -746,6 +747,7 @@ resubmit:
return;
free:
kfree_skb(skb);
+ kfree(rx_buf);
urb->context = NULL;
}

@@ -791,7 +793,7 @@ static int ath9k_hif_usb_alloc_tx_urbs(s
init_usb_anchor(&hif_dev->mgmt_submitted);

for (i = 0; i < MAX_TX_URB_NUM; i++) {
- tx_buf = kzalloc(sizeof(struct tx_buf), GFP_KERNEL);
+ tx_buf = kzalloc(sizeof(*tx_buf), GFP_KERNEL);
if (!tx_buf)
goto err;

@@ -828,8 +830,9 @@ static void ath9k_hif_usb_dealloc_rx_urb

static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev)
{
- struct urb *urb = NULL;
+ struct rx_buf *rx_buf = NULL;
struct sk_buff *skb = NULL;
+ struct urb *urb = NULL;
int i, ret;

init_usb_anchor(&hif_dev->rx_submitted);
@@ -837,6 +840,12 @@ static int ath9k_hif_usb_alloc_rx_urbs(s

for (i = 0; i < MAX_RX_URB_NUM; i++) {

+ rx_buf = kzalloc(sizeof(*rx_buf), GFP_KERNEL);
+ if (!rx_buf) {
+ ret = -ENOMEM;
+ goto err_rxb;
+ }
+
/* Allocate URB */
urb = usb_alloc_urb(0, GFP_KERNEL);
if (urb == NULL) {
@@ -851,11 +860,14 @@ static int ath9k_hif_usb_alloc_rx_urbs(s
goto err_skb;
}

+ rx_buf->hif_dev = hif_dev;
+ rx_buf->skb = skb;
+
usb_fill_bulk_urb(urb, hif_dev->udev,
usb_rcvbulkpipe(hif_dev->udev,
USB_WLAN_RX_PIPE),
skb->data, MAX_RX_BUF_SIZE,
- ath9k_hif_usb_rx_cb, skb);
+ ath9k_hif_usb_rx_cb, rx_buf);

/* Anchor URB */
usb_anchor_urb(urb, &hif_dev->rx_submitted);
@@ -881,6 +893,8 @@ err_submit:
err_skb:
usb_free_urb(urb);
err_urb:
+ kfree(rx_buf);
+err_rxb:
ath9k_hif_usb_dealloc_rx_urbs(hif_dev);
return ret;
}
@@ -892,14 +906,21 @@ static void ath9k_hif_usb_dealloc_reg_in

static int ath9k_hif_usb_alloc_reg_in_urbs(struct hif_device_usb *hif_dev)
{
- struct urb *urb = NULL;
+ struct rx_buf *rx_buf = NULL;
struct sk_buff *skb = NULL;
+ struct urb *urb = NULL;
int i, ret;

init_usb_anchor(&hif_dev->reg_in_submitted);

for (i = 0; i < MAX_REG_IN_URB_NUM; i++) {

+ rx_buf = kzalloc(sizeof(*rx_buf), GFP_KERNEL);
+ if (!rx_buf) {
+ ret = -ENOMEM;
+ goto err_rxb;
+ }
+
/* Allocate URB */
urb = usb_alloc_urb(0, GFP_KERNEL);
if (urb == NULL) {
@@ -914,11 +935,14 @@ static int ath9k_hif_usb_alloc_reg_in_ur
goto err_skb;
}

+ rx_buf->hif_dev = hif_dev;
+ rx_buf->skb = skb;
+
usb_fill_int_urb(urb, hif_dev->udev,
usb_rcvintpipe(hif_dev->udev,
USB_REG_IN_PIPE),
skb->data, MAX_REG_IN_BUF_SIZE,
- ath9k_hif_usb_reg_in_cb, skb, 1);
+ ath9k_hif_usb_reg_in_cb, rx_buf, 1);

/* Anchor URB */
usb_anchor_urb(urb, &hif_dev->reg_in_submitted);
@@ -944,6 +968,8 @@ err_submit:
err_skb:
usb_free_urb(urb);
err_urb:
+ kfree(rx_buf);
+err_rxb:
ath9k_hif_usb_dealloc_reg_in_urbs(hif_dev);
return ret;
}
--- a/drivers/net/wireless/ath/ath9k/hif_usb.h
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.h
@@ -84,6 +84,11 @@ struct tx_buf {
struct list_head list;
};

+struct rx_buf {
+ struct sk_buff *skb;
+ struct hif_device_usb *hif_dev;
+};
+
#define HIF_USB_TX_STOP BIT(0)
#define HIF_USB_TX_FLUSH BIT(1)