[PATCH 4.19 13/27] NFC: st21nfca: Fix memory leak in device probe and remove

From: Greg Kroah-Hartman
Date: Mon Jan 03 2022 - 09:25:30 EST


From: Wei Yongjun <weiyongjun1@xxxxxxxxxx>

[ Upstream commit 1b9dadba502234eea7244879b8d5d126bfaf9f0c ]

'phy->pending_skb' is alloced when device probe, but forgot to free
in the error handling path and remove path, this cause memory leak
as follows:

unreferenced object 0xffff88800bc06800 (size 512):
comm "8", pid 11775, jiffies 4295159829 (age 9.032s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000d66c09ce>] __kmalloc_node_track_caller+0x1ed/0x450
[<00000000c93382b3>] kmalloc_reserve+0x37/0xd0
[<000000005fea522c>] __alloc_skb+0x124/0x380
[<0000000019f29f9a>] st21nfca_hci_i2c_probe+0x170/0x8f2

Fix it by freeing 'pending_skb' in error and remove.

Fixes: 68957303f44a ("NFC: ST21NFCA: Add driver for STMicroelectronics ST21NFCA NFC Chip")
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/nfc/st21nfca/i2c.c | 29 ++++++++++++++++++++---------
1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/drivers/nfc/st21nfca/i2c.c b/drivers/nfc/st21nfca/i2c.c
index 1b347096422ff..ebea3b4dd8e1b 100644
--- a/drivers/nfc/st21nfca/i2c.c
+++ b/drivers/nfc/st21nfca/i2c.c
@@ -544,7 +544,8 @@ static int st21nfca_hci_i2c_probe(struct i2c_client *client,
phy->gpiod_ena = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
if (IS_ERR(phy->gpiod_ena)) {
nfc_err(dev, "Unable to get ENABLE GPIO\n");
- return PTR_ERR(phy->gpiod_ena);
+ r = PTR_ERR(phy->gpiod_ena);
+ goto out_free;
}

phy->se_status.is_ese_present =
@@ -555,7 +556,7 @@ static int st21nfca_hci_i2c_probe(struct i2c_client *client,
r = st21nfca_hci_platform_init(phy);
if (r < 0) {
nfc_err(&client->dev, "Unable to reboot st21nfca\n");
- return r;
+ goto out_free;
}

r = devm_request_threaded_irq(&client->dev, client->irq, NULL,
@@ -564,15 +565,23 @@ static int st21nfca_hci_i2c_probe(struct i2c_client *client,
ST21NFCA_HCI_DRIVER_NAME, phy);
if (r < 0) {
nfc_err(&client->dev, "Unable to register IRQ handler\n");
- return r;
+ goto out_free;
}

- return st21nfca_hci_probe(phy, &i2c_phy_ops, LLC_SHDLC_NAME,
- ST21NFCA_FRAME_HEADROOM,
- ST21NFCA_FRAME_TAILROOM,
- ST21NFCA_HCI_LLC_MAX_PAYLOAD,
- &phy->hdev,
- &phy->se_status);
+ r = st21nfca_hci_probe(phy, &i2c_phy_ops, LLC_SHDLC_NAME,
+ ST21NFCA_FRAME_HEADROOM,
+ ST21NFCA_FRAME_TAILROOM,
+ ST21NFCA_HCI_LLC_MAX_PAYLOAD,
+ &phy->hdev,
+ &phy->se_status);
+ if (r)
+ goto out_free;
+
+ return 0;
+
+out_free:
+ kfree_skb(phy->pending_skb);
+ return r;
}

static int st21nfca_hci_i2c_remove(struct i2c_client *client)
@@ -585,6 +594,8 @@ static int st21nfca_hci_i2c_remove(struct i2c_client *client)

if (phy->powered)
st21nfca_hci_i2c_disable(phy);
+ if (phy->pending_skb)
+ kfree_skb(phy->pending_skb);

return 0;
}
--
2.34.1