wifi: rtl8xxxu: Fix the error handling of the probe function

When the driver fails at ieee80211_alloc_hw() at the probe time, the
driver will free the 'hw' which is not allocated, causing a bug.

The following log can reveal it:

[   15.981294] BUG: KASAN: user-memory-access in mutex_is_locked+0xe/0x40
[   15.981558] Read of size 8 at addr 0000000000001ab0 by task modprobe/373
[   15.982583] Call Trace:
[   15.984282]  ieee80211_free_hw+0x22/0x390
[   15.984446]  rtl8xxxu_probe+0x3a1/0xab30 [rtl8xxxu]

Fix the bug by changing the order of the error handling.

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220716130444.2950690-1-zheyuma97@gmail.com

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index 33a1d9143038f005cb9a132e6f726d71a7c5ac76..c66f0726b2535c6321c7815bc9eedecd6604b40a 100644 (file)
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -6658,7 +6658,7 @@ static int rtl8xxxu_probe(struct usb_interface *interface,
        if (!hw) {
                ret = -ENOMEM;
                priv = NULL;
-               goto exit;
+               goto err_put_dev;
        }
 
        priv = hw->priv;
@@ -6680,24 +6680,24 @@ static int rtl8xxxu_probe(struct usb_interface *interface,
 
        ret = rtl8xxxu_parse_usb(priv, interface);
        if (ret)
-               goto exit;
+               goto err_set_intfdata;
 
        ret = rtl8xxxu_identify_chip(priv);
        if (ret) {
                dev_err(&udev->dev, "Fatal - failed to identify chip\n");
-               goto exit;
+               goto err_set_intfdata;
        }
 
        ret = rtl8xxxu_read_efuse(priv);
        if (ret) {
                dev_err(&udev->dev, "Fatal - failed to read EFuse\n");
-               goto exit;
+               goto err_set_intfdata;
        }
 
        ret = priv->fops->parse_efuse(priv);
        if (ret) {
                dev_err(&udev->dev, "Fatal - failed to parse EFuse\n");
-               goto exit;
+               goto err_set_intfdata;
        }
 
        rtl8xxxu_print_chipinfo(priv);
@@ -6705,12 +6705,12 @@ static int rtl8xxxu_probe(struct usb_interface *interface,
        ret = priv->fops->load_firmware(priv);
        if (ret) {
                dev_err(&udev->dev, "Fatal - failed to load firmware\n");
-               goto exit;
+               goto err_set_intfdata;
        }
 
        ret = rtl8xxxu_init_device(hw);
        if (ret)
-               goto exit;
+               goto err_set_intfdata;
 
        hw->wiphy->max_scan_ssids = 1;
        hw->wiphy->max_scan_ie_len = IEEE80211_MAX_DATA_LEN;
@@ -6760,12 +6760,12 @@ static int rtl8xxxu_probe(struct usb_interface *interface,
        if (ret) {
                dev_err(&udev->dev, "%s: Failed to register: %i\n",
                        __func__, ret);
-               goto exit;
+               goto err_set_intfdata;
        }
 
        return 0;
 
-exit:
+err_set_intfdata:
        usb_set_intfdata(interface, NULL);
 
        if (priv) {
@@ -6773,9 +6773,10 @@ exit:
                mutex_destroy(&priv->usb_buf_mutex);
                mutex_destroy(&priv->h2c_mutex);
        }
-       usb_put_dev(udev);
 
        ieee80211_free_hw(hw);
+err_put_dev:
+       usb_put_dev(udev);
 
        return ret;
 }