Commit 7ce2c18e authored Sep 30, 2020 by Anmol Karn Committed by Greg Kroah-Hartman Dec 29, 2020

Bluetooth: Fix null pointer dereference in hci_event_packet()



[ Upstream commit 6dfccd13db2ff2b709ef60a50163925d477549aa ]

AMP_MGR is getting derefernced in hci_phy_link_complete_evt(), when called
from hci_event_packet() and there is a possibility, that hcon->amp_mgr may
not be found when accessing after initialization of hcon.

- net/bluetooth/hci_event.c:4945
The bug seems to get triggered in this line:

bredr_hcon = hcon->amp_mgr->l2cap_conn->hcon;

Fix it by adding a NULL check for the hcon->amp_mgr before checking the ev-status.

Fixes: d5e91192 ("Bluetooth: AMP: Process Physical Link Complete evt")
Reported-and-tested-by:  <syzbot+0bef568258653cff272f@syzkaller.appspotmail.com>
Link: https://syzkaller.appspot.com/bug?extid=0bef568258653cff272f


Signed-off-by: Anmol Karn <anmol.karan123@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 76e915e7

net/bluetooth/hci_event.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -4350,6 +4350,11 @@ static void hci_phy_link_complete_evt(struct hci_dev *hdev,
		return;
		}

		if (!hcon->amp_mgr) {
		hci_dev_unlock(hdev);
		return;
		}

		if (ev->status) {
		hci_conn_del(hcon);
		hci_dev_unlock(hdev);