| Message ID | 20201223180446.17207-1-yepeilin.cs@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [4.14,4.9,4.4-stable] Bluetooth: Fix slab-out-of-bounds read in hci_le_direct_adv_report_evt() | expand |
On Wed, Dec 23, 2020 at 01:04:46PM -0500, Peilin Ye wrote: > commit f7e0e8b2f1b0a09b527885babda3e912ba820798 upstream. > > `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. > > Backporting notes: > - Rebased on linux-4.14.y, commit 3f2ecb86cb90 ("Linux 4.14.212") > - Retested by syzbot > > 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> > --- > net/bluetooth/hci_event.c | 12 +++++------- > 1 file changed, 5 insertions(+), 7 deletions(-) Thanks for the backport, now queued up! greg k-h
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index ba12bf8de826..0db218b14bf3 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -5141,20 +5141,18 @@ 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); - ptr += sizeof(*ev); - } - hci_dev_unlock(hdev); }
commit f7e0e8b2f1b0a09b527885babda3e912ba820798 upstream. `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. Backporting notes: - Rebased on linux-4.14.y, commit 3f2ecb86cb90 ("Linux 4.14.212") - Retested by syzbot 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> --- net/bluetooth/hci_event.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)