lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 13 Jan 2022 12:46:43 -0800 From: Luiz Augusto von Dentz <luiz.dentz@...il.com> To: Soenke Huster <soenke.huster@...oes.de> Cc: Marcel Holtmann <marcel@...tmann.org>, Johan Hedberg <johan.hedberg@...il.com>, "David S. Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>, "linux-bluetooth@...r.kernel.org" <linux-bluetooth@...r.kernel.org>, "open list:NETWORKING [GENERAL]" <netdev@...r.kernel.org>, Linux Kernel Mailing List <linux-kernel@...r.kernel.org> Subject: Re: [PATCH v2] Bluetooth: fix null ptr deref on hci_sync_conn_complete_evt Hi Soenke, On Thu, Jan 13, 2022 at 8:41 AM Soenke Huster <soenke.huster@...oes.de> wrote: > > This event is specified just for SCO and eSCO link types. > On the reception of a HCI_Synchronous_Connection_Complete for a BDADDR > of an existing LE connection, LE link type and a status that triggers the > second case of the packet processing a NULL pointer dereference happens, > as conn->link is NULL. > > Signed-off-by: Soenke Huster <soenke.huster@...oes.de> > --- > v2: Fixed the obviously wrong boolean comparison > > I found this null pointer dereference while fuzzing bluetooth-next. > On the described behaviour, a null ptr deref in line 4723 happens, as > conn->link is NULL. According to the Core spec, Link_Type must be SCO or eSCO, > all other values are reserved for future use. Checking that mitigates a null > pointer dereference. > > 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 05997dff5666..d68f5640fb38 100644 > --- a/net/bluetooth/hci_event.c > +++ b/net/bluetooth/hci_event.c > @@ -4661,6 +4661,11 @@ static void hci_sync_conn_complete_evt(struct hci_dev *hdev, void *data, > struct hci_ev_sync_conn_complete *ev = data; > struct hci_conn *conn; > > + if (!(ev->link_type == SCO_LINK || ev->link_type == ESCO_LINK)) { > + bt_dev_err(hdev, "Ignoring connect complete event for invalid link type"); > + return; > + } I rather have this as a switch statement: switch (ev->link_type) case SCO_LINK: case ESCO_LINK: break; default: /* Add comment where the spec states this is invalid */ bt_dev_err(hdev, "Ignoring connect complete event for invalid link type"); return; > bt_dev_dbg(hdev, "status 0x%2.2x", ev->status); > > hci_dev_lock(hdev); > -- > 2.34.1 > -- Luiz Augusto von Dentz
Powered by blists - more mailing lists