[PATCH] net/bluetooth: Fix bound check in event handling

From: Tomas Bortoli
Date: Mon Mar 04 2019 - 15:23:29 EST


hci_inquiry_result_with_rssi_evt() can perform out of bound reads
on skb->data as a bound check is missing.

Signed-off-by: Tomas Bortoli <tomasbortoli@xxxxxxxxx>
Reported-by: syzbot+cec7a50c412a2c03f8f5@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: syzbot+660883c56e2fa65d4497@xxxxxxxxxxxxxxxxxxxxxxxxx
---
v2:
- changed sizeof(info) into sizeof(*info), as it should be.
- simplified expression in if

net/bluetooth/hci_event.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index ac2826ce162b..4cbad1e1a322 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3978,11 +3978,15 @@ static void hci_inquiry_result_with_rssi_evt(struct hci_dev *hdev,

if ((skb->len - 1) / num_rsp != sizeof(struct inquiry_info_with_rssi)) {
struct inquiry_info_with_rssi_and_pscan_mode *info;
+ void *data_end = (void *)skb->data + skb->len;
info = (void *) (skb->data + 1);

for (; num_rsp; num_rsp--, info++) {
u32 flags;

+ if ((void *)info + sizeof(*info) > data_end)
+ break;
+
bacpy(&data.bdaddr, &info->bdaddr);
data.pscan_rep_mode = info->pscan_rep_mode;
data.pscan_period_mode = info->pscan_period_mode;
--
2.11.0