On Mon, Oct 9, 2023, at 21:48, Kees Cook wrote: > On Mon, Oct 09, 2023 at 08:23:08PM +0200, Arnd Bergmann wrote: >> On Mon, Oct 9, 2023, at 18:02, Kees Cook wrote: >> > On Mon, Oct 09, 2023 at 05:36:55PM +0200, Arnd Bergmann wrote: >> >> On Mon, Oct 9, 2023, at 15:48, Arnd Bergmann wrote: >> >> >> >> Sorry, I have to retract this, something went wrong on my >> >> testing and I now see the same problem in some configs regardless >> >> of whether the patch is applied or not. >> > >> > Perhaps turn them into macros instead? >> >> I just tried that and still see the problem even with the macro, >> so whatever gcc is doing must be a different issue. Maybe it >> has correctly found a codepath that triggers this? >> >> If you are able to help debug the issue better, >> see these defconfigs for examples: >> >> https://pastebin.com/raw/pC8Lnrn2 >> https://pastebin.com/raw/yb965unC > > This seems like a GCC bug. It is complaining about &hdev->bdaddr for > some reason. This silences it: > > - if (!bacmp(&hdev->bdaddr, &ev->bdaddr)) { > + a = hdev->bdaddr; > + if (!bacmp(&a, &ev->bdaddr)) { Right, I see this addresses all instances. I tried another thing and this also seems to address them for me: --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -3273,7 +3273,7 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data, /* Reject incoming connection from device with same BD ADDR against * CVE-2020-26555 */ - if (!bacmp(&hdev->bdaddr, &ev->bdaddr)) { + if (hdev && !bacmp(&hdev->bdaddr, &ev->bdaddr)) { bt_dev_dbg(hdev, "Reject connection with same BD_ADDR %pMR\n", &ev->bdaddr); hci_reject_conn(hdev, &ev->bdaddr); and also this one does the trick: --- a/include/net/bluetooth/bluetooth.h +++ b/include/net/bluetooth/bluetooth.h @@ -266,7 +266,7 @@ void bt_err_ratelimited(const char *fmt, ...); #define BT_DBG(fmt, ...) pr_debug(fmt "\n", ##__VA_ARGS__) #endif -#define bt_dev_name(hdev) ((hdev) ? (hdev)->name : "null") +#define bt_dev_name(hdev) ((hdev)->name) #define bt_dev_info(hdev, fmt, ...) \ BT_INFO("%s: " fmt, bt_dev_name(hdev), ##__VA_ARGS__) So what is actually going on is that the bt_dev_dbg() introduces the idea that hdev might be NULL because of the check. Arnd
