On Sat, Aug 29, 2020 at 10:27:12PM +0530, Anmol Karn wrote: > Fix null pointer deref in hci_phy_link_complete_evt, there was no > checking there for the hcon->amp_mgr->l2cap_conn->hconn, and also > in hci_cmd_work, for hdev->sent_cmd. > > To fix this issue Add pointer checking in hci_cmd_work and > hci_phy_link_complete_evt. > [Linux-next-20200827] > > This patch corrected some mistakes from previous patch. > > Reported-by: syzbot+0bef568258653cff272f@xxxxxxxxxxxxxxxxxxxxxxxxx > Link: https://syzkaller.appspot.com/bug?id=0d93140da5a82305a66a136af99b088b75177b99 > Signed-off-by: Anmol Karn <anmol.karan123@xxxxxxxxx> > --- > net/bluetooth/hci_core.c | 5 ++++- > net/bluetooth/hci_event.c | 4 ++++ > 2 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c > index 68bfe57b6625..996efd654e7a 100644 > --- a/net/bluetooth/hci_core.c > +++ b/net/bluetooth/hci_core.c > @@ -4922,7 +4922,10 @@ static void hci_cmd_work(struct work_struct *work) > > kfree_skb(hdev->sent_cmd); > > - hdev->sent_cmd = skb_clone(skb, GFP_KERNEL); > + if (hdev->sent_cmd) { > + hdev->sent_cmd = skb_clone(skb, GFP_KERNEL); > + } How can sent_cmd be NULL here? Are you sure something previous to this shouldn't be fixed instead? > + > if (hdev->sent_cmd) { > if (hci_req_status_pend(hdev)) > hci_dev_set_flag(hdev, HCI_CMD_PENDING); > diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c > index 4b7fc430793c..1e7d9bee9111 100644 > --- a/net/bluetooth/hci_event.c > +++ b/net/bluetooth/hci_event.c > @@ -4941,6 +4941,10 @@ static void hci_phy_link_complete_evt(struct hci_dev *hdev, > hci_dev_unlock(hdev); > return; > } > + if (!(hcon->amp_mgr->l2cap_conn->hcon)) { > + hci_dev_unlock(hdev); > + return; > + } How can this be triggered? thanks, greg k-h
