The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f7e0e8b2f1b0a09b527885babda3e912ba820798 Mon Sep 17 00:00:00 2001
From: Peilin Ye yepeilin.cs@gmail.com Date: Wed, 9 Sep 2020 03:17:00 -0400 Subject: [PATCH] Bluetooth: Fix slab-out-of-bounds read in hci_le_direct_adv_report_evt()
`num_reports` is not being properly checked. A malformed event packet with a large `num_reports` number makes hci_le_direct_adv_report_evt() read out of bounds. Fix it.
Cc: stable@vger.kernel.org Fixes: 2f010b55884e ("Bluetooth: Add support for handling LE Direct Advertising Report events") Reported-and-tested-by: syzbot+24ebd650e20bd263ca01@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=24ebd650e20bd263ca01 Signed-off-by: Peilin Ye yepeilin.cs@gmail.com Signed-off-by: Marcel Holtmann marcel@holtmann.org
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index e72982b69f6b..17a72695865b 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -5873,21 +5873,19 @@ static void hci_le_direct_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) { u8 num_reports = skb->data[0]; - void *ptr = &skb->data[1]; + struct hci_ev_le_direct_adv_info *ev = (void *)&skb->data[1];
- hci_dev_lock(hdev); + if (!num_reports || skb->len < num_reports * sizeof(*ev) + 1) + return;
- while (num_reports--) { - struct hci_ev_le_direct_adv_info *ev = ptr; + hci_dev_lock(hdev);
+ for (; num_reports; num_reports--, ev++) process_adv_report(hdev, ev->evt_type, &ev->bdaddr, ev->bdaddr_type, &ev->direct_addr, ev->direct_addr_type, ev->rssi, NULL, 0, false);
- ptr += sizeof(*ev); - } - hci_dev_unlock(hdev); }