| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 037/132] Bluetooth: Fix null pointer dereference in hci_event_packet() | Date | Mon, 28 Dec 2020 13:48:41 +0100 |
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From: Anmol Karn <anmol.karan123@gmail.com>
[ 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: d5e911928bd8 ("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> --- net/bluetooth/hci_event.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 70a73e7dbf161..586c005bdc1ee 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -4336,6 +4336,11 @@ 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); -- 2.27.0
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