| Message ID | 20220113164042.259990-1-soenke.huster@eknoes.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] Bluetooth: fix null ptr deref on hci_sync_conn_complete_evt | expand |
| Context | Check | Description |
|---|---|---|
| tedd_an/checkpatch | success | Checkpatch PASS |
| tedd_an/gitlint | success | Gitlint PASS |
| tedd_an/buildkernel | success | Build Kernel PASS |
| tedd_an/incremental_build | success | Pass |
| tedd_an/testrunnersetup | success | Test Runner Setup PASS |
| tedd_an/testrunnerl2cap-tester | success | Total: 40, Passed: 40 (100.0%), Failed: 0, Not Run: 0 |
| tedd_an/testrunnerbnep-tester | success | Total: 1, Passed: 1 (100.0%), Failed: 0, Not Run: 0 |
| tedd_an/testrunnermgmt-tester | success | Total: 493, Passed: 493 (100.0%), Failed: 0, Not Run: 0 |
| tedd_an/testrunnerrfcomm-tester | success | Total: 9, Passed: 9 (100.0%), Failed: 0, Not Run: 0 |
| tedd_an/testrunnersco-tester | success | Total: 12, Passed: 12 (100.0%), Failed: 0, Not Run: 0 |
| tedd_an/testrunnersmp-tester | success | Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0 |
| tedd_an/testrunneruserchan-tester | success | Total: 4, Passed: 4 (100.0%), Failed: 0, Not Run: 0 |
Hi Soenke, On Thu, Jan 13, 2022 at 8:41 AM Soenke Huster <soenke.huster@eknoes.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@eknoes.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 >
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; + } + bt_dev_dbg(hdev, "status 0x%2.2x", ev->status); hci_dev_lock(hdev);
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@eknoes.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(+)