Re: [PATCH] net/bluetooth: Fix bound check in event handling
From: Marcel Holtmann <marcel@holtmann.org>
Date: 2019-03-02 16:46:53
Also in:
linux-bluetooth, lkml
Hi Tomas,
quoted hunk ↗ jump to hunk
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 <redacted> Reported-by: syzbot+cec7a50c412a2c03f8f5@syzkaller.appspotmail.com Reported-by: syzbot+660883c56e2fa65d4497@syzkaller.appspotmail.com --- 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; +
first of all, the loop exists twice here. If one is vulnerable, then the second is a well. And second, can we not just do this inside the for-condition check or a lot simpler than this void casting fun. Regards Marcel