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

From: Tomas Bortoli
Date: Thu Feb 28 2019 - 15:00:11 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
---
Syzkaler reports:
https://syzkaller.appspot.com/bug?id=d708485af9edc3af35f3b4d554e827c6c8bf6b0f
https://syzkaller.appspot.com/bug?id=3acd1155d48a5acc5d76711568b04926945a6885

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..aa953d23bb72 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3983,6 +3983,10 @@ static void hci_inquiry_result_with_rssi_evt(struct hci_dev *hdev,
for (; num_rsp; num_rsp--, info++) {
u32 flags;

+ if ((void *)(info + sizeof(info)) >
+ (void *)(skb->data + skb->len))
+ 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