[PATCH AUTOSEL 5.18 86/93] wifi: rtl8xxxu: Fix the error handling of the probe function

Sasha Levin
2022-08-11T16:10:56Z

From: Zheyu Ma <zheyuma97@gmail.com>

[ Upstream commit 13876f2a087ad352bf640a7a0a4a4229ea6e9e4f ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 21 ++++++++++---------
1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index 06d59ffb7444..7ff30de10a7c 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -6611,7 +6611,7 @@ static int rtl8xxxu_probe(struct usb_interface *interface,
if (!hw) {
ret = -ENOMEM;
priv = NULL;
- goto exit;
+ goto err_put_dev;
}

priv = hw->priv;
@@ -6633,24 +6633,24 @@ 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);
@@ -6658,12 +6658,12 @@ 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;
@@ -6713,12 +6713,12 @@ 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) {
@@ -6726,9 +6726,10 @@ static int rtl8xxxu_probe(struct usb_interface *interface,
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;
}
--
2.35.1