[Linux-kernel-mentees] [PATCH] net: bluetooth: Fix null pointer dereference in hci_event_packet()

[Anmol Karn]

Prevent hci_phy_link_complete_evt() from dereferencing 'hcon->amp_mgr'
as NULL. Fix it by adding pointer check for it.

Reported-and-tested-by: syzbot+0bef568258653cff272f@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://syzkaller.appspot.com/bug?extid=0bef568258653cff272f
Signed-off-by: Anmol Karn <anmol.karan123@xxxxxxxxx>
---
 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 4b7fc430793c..871e16804433 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4936,6 +4936,11 @@ static void hci_phy_link_complete_evt(struct hci_dev *hdev,
 		return;
 	}
 
+	if (IS_ERR_OR_NULL(hcon->amp_mgr)) {
+		hci_dev_unlock(hdev);
+		return;
+	}
+
 	if (ev->status) {
 		hci_conn_del(hcon);
 		hci_dev_unlock(hdev);
-- 
2.28.0