[PATCH v3 1/2] usb: hso: fix error handling code of hso_create_net_device

From: Dongliang Mu
Date: Wed Jul 14 2021 - 05:14:32 EST


The current error handling code of hso_create_net_device is
hso_free_net_device, no matter which errors lead to. For example,
WARNING in hso_free_net_device [1].

Fix this by refactoring the error handling code of
hso_create_net_device by handling different errors by different code.

[1] https://syzkaller.appspot.com/bug?id=66eff8d49af1b28370ad342787413e35bbe76efe

Reported-by: syzbot+44d53c7255bb1aea22d2@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 5fcfb6d0bfcd ("hso: fix bailout in error case of probe")
Signed-off-by: Dongliang Mu <mudongliangabcd@xxxxxxxxx>
---
v1->v2: change labels according to the comment of Dan Carpenter
v2->v3: change the style of error handling labels
drivers/net/usb/hso.c | 33 +++++++++++++++++++++++----------
1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index 54ef8492ca01..39c4e88eab62 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -2495,7 +2495,7 @@ static struct hso_device *hso_create_net_device(struct usb_interface *interface,
hso_net_init);
if (!net) {
dev_err(&interface->dev, "Unable to create ethernet device\n");
- goto exit;
+ goto err_hso_dev;
}

hso_net = netdev_priv(net);
@@ -2508,13 +2508,13 @@ static struct hso_device *hso_create_net_device(struct usb_interface *interface,
USB_DIR_IN);
if (!hso_net->in_endp) {
dev_err(&interface->dev, "Can't find BULK IN endpoint\n");
- goto exit;
+ goto err_net;
}
hso_net->out_endp = hso_get_ep(interface, USB_ENDPOINT_XFER_BULK,
USB_DIR_OUT);
if (!hso_net->out_endp) {
dev_err(&interface->dev, "Can't find BULK OUT endpoint\n");
- goto exit;
+ goto err_net;
}
SET_NETDEV_DEV(net, &interface->dev);
SET_NETDEV_DEVTYPE(net, &hso_type);
@@ -2523,18 +2523,18 @@ static struct hso_device *hso_create_net_device(struct usb_interface *interface,
for (i = 0; i < MUX_BULK_RX_BUF_COUNT; i++) {
hso_net->mux_bulk_rx_urb_pool[i] = usb_alloc_urb(0, GFP_KERNEL);
if (!hso_net->mux_bulk_rx_urb_pool[i])
- goto exit;
+ goto err_mux_bulk_rx;
hso_net->mux_bulk_rx_buf_pool[i] = kzalloc(MUX_BULK_RX_BUF_SIZE,
GFP_KERNEL);
if (!hso_net->mux_bulk_rx_buf_pool[i])
- goto exit;
+ goto err_mux_bulk_rx;
}
hso_net->mux_bulk_tx_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!hso_net->mux_bulk_tx_urb)
- goto exit;
+ goto err_mux_bulk_rx;
hso_net->mux_bulk_tx_buf = kzalloc(MUX_BULK_TX_BUF_SIZE, GFP_KERNEL);
if (!hso_net->mux_bulk_tx_buf)
- goto exit;
+ goto err_free_tx_urb;

add_net_device(hso_dev);

@@ -2542,7 +2542,7 @@ static struct hso_device *hso_create_net_device(struct usb_interface *interface,
result = register_netdev(net);
if (result) {
dev_err(&interface->dev, "Failed to register device\n");
- goto exit;
+ goto err_free_tx_buf;
}

hso_log_port(hso_dev);
@@ -2550,8 +2550,21 @@ static struct hso_device *hso_create_net_device(struct usb_interface *interface,
hso_create_rfkill(hso_dev, interface);

return hso_dev;
-exit:
- hso_free_net_device(hso_dev, true);
+
+err_free_tx_buf:
+ remove_net_device(hso_dev);
+ kfree(hso_net->mux_bulk_tx_buf);
+err_free_tx_urb:
+ usb_free_urb(hso_net->mux_bulk_tx_urb);
+err_mux_bulk_rx:
+ for (i = 0; i < MUX_BULK_RX_BUF_COUNT; i++) {
+ usb_free_urb(hso_net->mux_bulk_rx_urb_pool[i]);
+ kfree(hso_net->mux_bulk_rx_buf_pool[i]);
+ }
+err_net:
+ free_netdev(net);
+err_hso_dev:
+ kfree(hso_dev);
return NULL;
}

--
2.25.1