From patchwork Tue May 17 16:33:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Albert Wang X-Patchwork-Id: 573646 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 765CEC433F5 for ; Tue, 17 May 2022 16:33:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350929AbiEQQdi (ORCPT ); Tue, 17 May 2022 12:33:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350923AbiEQQdh (ORCPT ); Tue, 17 May 2022 12:33:37 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAE004E396 for ; Tue, 17 May 2022 09:33:36 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-2fb7cb07885so161798547b3.23 for ; Tue, 17 May 2022 09:33:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=Nst/okWzt+1Pt7btm5FYdNUScd4Lw2KRfwoUVrWaXsw=; b=NUjqy/+bSbXrnYySDW8oHLK7ZvYo8UxSan1NjQOA0bI65RPnMb9WnR8tImW6L88OHi V36uWEmPNdeRafPTRd9eC+JpOr60TfgZdy3f6mTSXAZp8MyQxR1Twg85xE1SWCE/MC75 Fg80X4tCgEOggsX6AKjdLhvX4UPF0MEKnfv02sHr60SQ9QCLpZEfTTLp3dlkexRmhzy+ tCwSZJNpk++N6G+lwt4t+097KiDUTySpn9hD/KkoEITW2KP9SMs3jHNCnLEUypJRX14J fcOf5HP9xcwDUhK5vMIbCeS6kGgCZKbthNoXMuwmGql1IZN+Nwv9UfWZ1EpL2cAYGk6s UGjw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=Nst/okWzt+1Pt7btm5FYdNUScd4Lw2KRfwoUVrWaXsw=; b=0XQqO7KVQ2lFPPZvyHNbNJ3VDGTPtwaKHTztiGAhgQne9AEjRWoqW8DOj+Gg50ym0j 9FkmwIrI28H7IUJLL7j/7A+Q+HuorDhEcznWXLyz79xM3akK1i/12t7WZXHkwAMHMObG /FahfMnF1rjB3PW4iKXQV1OC1pCWwRWADxvXPXn+wKL/HOrPKETGhgBHH49jzV2gkEcg dYUr/E1Pvg64dydrPu4YJWnXjYRUnkqAZnhSVjVsVs2kOlTMSAlzZelvP1N2ZzgFODYE HIjB+rEV1WTwIdOjl30j8/U6Sk4m6AbOAoJ/PIE0STUHkEko3JQ8CQl8DUMLlx0pClJb H08g== X-Gm-Message-State: AOAM533U3GlPOtu0WNvCbcVG0Xsg1WX43GIr7oCNuY32PXpadWur/I9z Vdt6IUU6hS2gs5f/F0gliz5A5PI4LFs5fbKskfA= X-Google-Smtp-Source: ABdhPJzQMrJAB31cWyVhMrErVTIoNbT/VAktbZdlxzhC/MUZI8Jyjq+7+cHrQz0Gq+msR06t6x8V7DPcPbfvFWxOi6c= X-Received: from albertccwang.ntc.corp.google.com ([2401:fa00:fc:202:e585:74ab:1a58:5276]) (user=albertccwang job=sendgmr) by 2002:a25:d741:0:b0:64d:b05e:f263 with SMTP id o62-20020a25d741000000b0064db05ef263mr11319662ybg.72.1652805215997; Tue, 17 May 2022 09:33:35 -0700 (PDT) Date: Wed, 18 May 2022 00:33:28 +0800 Message-Id: <20220517163328.3135065-1-albertccwang@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.36.1.124.g0e6072fb45-goog Subject: [PATCH v4] usb: dwc3: gadget: Move null pinter check to proper place From: Albert Wang To: balbi@kernel.org, gregkh@linuxfoundation.org, quic_jackp@quicinc.com Cc: badhri@google.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Albert Wang Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org When dwc3_gadget_ep_cleanup_completed_requests() called to dwc3_gadget_giveback() where the dwc3 lock is released, other thread is able to execute. In this situation, usb_ep_disable() gets the chance to clear endpoint descriptor pointer which leds to the null pointer dereference problem. So needs to move the null pointer check to a proper place. Example call stack: Thread#1: dwc3_thread_interrupt() spin_lock -> dwc3_process_event_buf() -> dwc3_process_event_entry() -> dwc3_endpoint_interrupt() -> dwc3_gadget_endpoint_trbs_complete() -> dwc3_gadget_ep_cleanup_completed_requests() ... -> dwc3_giveback() spin_unlock Thread#2 executes Thread#2: configfs_composite_disconnect() -> __composite_disconnect() -> ffs_func_disable() -> ffs_func_set_alt() -> ffs_func_eps_disable() -> usb_ep_disable() wait for dwc3 spin_lock Thread#1 released lock clear endpoint.desc Fixes: 26288448120b ("usb: dwc3: gadget: Fix null pointer exception") Signed-off-by: Albert Wang --- drivers/usb/dwc3/gadget.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 19477f4bbf54..7edd4a5dc6af 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -3366,14 +3366,14 @@ static bool dwc3_gadget_endpoint_trbs_complete(struct dwc3_ep *dep, struct dwc3 *dwc = dep->dwc; bool no_started_trb = true; - if (!dep->endpoint.desc) - return no_started_trb; - dwc3_gadget_ep_cleanup_completed_requests(dep, event, status); if (dep->flags & DWC3_EP_END_TRANSFER_PENDING) goto out; + if (!dep->endpoint.desc) + return no_started_trb; + if (usb_endpoint_xfer_isoc(dep->endpoint.desc) && list_empty(&dep->started_list) && (list_empty(&dep->pending_list) || status == -EXDEV))