Felipe Balbi <balbi@xxxxxx> writes: >> > Because the fsl_udc_core driver shares one 'status_req' object for the >> > complete ep0 control transfer, it is not possible to prime the final >> > STATUS phase immediately after the IN transaction. E.g. ch9getstatus() >> > executed: >> > >> > | req = udc->status_req; >> > | ... >> > | list_add_tail(&req->queue, &ep->queue); >> > | if (ep0_prime_status(udc, EP_DIR_OUT)) >> > | .... >> > | struct fsl_req *req = udc->status_req; >> > | list_add_tail(&req->queue, &ep->queue); >> > >> > which corrupts the ep->queue list by inserting 'status_req' twice. This >> > causes a kernel oops e.g. when 'lsusb -v' is executed on the host. >> > >> > Patch delays the final 'ep0_prime_status(udc, EP_DIR_OUT))' by moving it >> > into the ep0 completion handler. >> > >> Enrico, thanks for pointing this problem. >> >> As "prime STATUS phase immediately after the IN transaction" is followed >> USB 2.0 spec, to fix this problem, it is better to add data_req for ep0. >> In fact, it is already at FSL i.mx internal code, just still not mainlined. > > so, do I get an Acked-by to this patch ? Does it need to go on v3.6-rc > or can it wait until v3.7 merge window ? Without this (or the mentioned data_req patch), I can crash a g_multi gadget by executing 'lsusb -v' as root on the host. Should not be exploitable (only a BUG_ON() is triggered) but issue should be fixed asap. Enrico -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
