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

[Tomas Bortoli]

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 <tomasbort...@gmail.com>
Reported-by: syzbot+cec7a50c412a2c03f...@syzkaller.appspotmail.com
Reported-by: syzbot+660883c56e2fa65d4...@syzkaller.appspotmail.com
---
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