[PATCH 5.4 021/123] net: nfc: fix bounds checking bugs on "pipe"

From: Greg Kroah-Hartman
Date: Tue Mar 17 2020 - 07:01:23 EST


From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

[ Upstream commit a3aefbfe45751bf7b338c181b97608e276b5bb73 ]

This is similar to commit 674d9de02aa7 ("NFC: Fix possible memory
corruption when handling SHDLC I-Frame commands") and commit d7ee81ad09f0
("NFC: nci: Add some bounds checking in nci_hci_cmd_received()") which
added range checks on "pipe".

The "pipe" variable comes skb->data[0] in nfc_hci_msg_rx_work().
It's in the 0-255 range. We're using it as the array index into the
hdev->pipes[] array which has NFC_HCI_MAX_PIPES (128) members.

Fixes: 118278f20aa8 ("NFC: hci: Add pipes table to reference them with a tuple {gate, host}")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/nfc/hci/core.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)

--- a/net/nfc/hci/core.c
+++ b/net/nfc/hci/core.c
@@ -181,13 +181,20 @@ exit:
void nfc_hci_cmd_received(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
struct sk_buff *skb)
{
- u8 gate = hdev->pipes[pipe].gate;
u8 status = NFC_HCI_ANY_OK;
struct hci_create_pipe_resp *create_info;
struct hci_delete_pipe_noti *delete_info;
struct hci_all_pipe_cleared_noti *cleared_info;
+ u8 gate;

- pr_debug("from gate %x pipe %x cmd %x\n", gate, pipe, cmd);
+ pr_debug("from pipe %x cmd %x\n", pipe, cmd);
+
+ if (pipe >= NFC_HCI_MAX_PIPES) {
+ status = NFC_HCI_ANY_E_NOK;
+ goto exit;
+ }
+
+ gate = hdev->pipes[pipe].gate;

switch (cmd) {
case NFC_HCI_ADM_NOTIFY_PIPE_CREATED:
@@ -375,8 +382,14 @@ void nfc_hci_event_received(struct nfc_h
struct sk_buff *skb)
{
int r = 0;
- u8 gate = hdev->pipes[pipe].gate;
+ u8 gate;
+
+ if (pipe >= NFC_HCI_MAX_PIPES) {
+ pr_err("Discarded event %x to invalid pipe %x\n", event, pipe);
+ goto exit;
+ }

+ gate = hdev->pipes[pipe].gate;
if (gate == NFC_HCI_INVALID_GATE) {
pr_err("Discarded event %x to unopened pipe %x\n", event, pipe);
goto exit;