From patchwork Tue Feb 22 13:41:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anssi Hannula X-Patchwork-Id: 12755116 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 B2BAAC433EF for ; Tue, 22 Feb 2022 13:52:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232572AbiBVNwX (ORCPT ); Tue, 22 Feb 2022 08:52:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50746 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232556AbiBVNwX (ORCPT ); Tue, 22 Feb 2022 08:52:23 -0500 X-Greylist: delayed 574 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 22 Feb 2022 05:51:57 PST Received: from mail.bitwise.fi (mail.bitwise.fi [109.204.228.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48EDB92874; Tue, 22 Feb 2022 05:51:57 -0800 (PST) Received: from localhost (localhost [127.0.0.1]) by mail.bitwise.fi (Postfix) with ESMTP id 0D08746001C; Tue, 22 Feb 2022 15:42:21 +0200 (EET) X-Virus-Scanned: Debian amavisd-new at Received: from mail.bitwise.fi ([127.0.0.1]) by localhost (mustetatti.dmz.bitwise.fi [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ckYSdGZrp2TM; Tue, 22 Feb 2022 15:42:19 +0200 (EET) Received: from localhost.net (fw1.dmz.bitwise.fi [192.168.69.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: anssiha) by mail.bitwise.fi (Postfix) with ESMTPSA id F313246000C; Tue, 22 Feb 2022 15:42:18 +0200 (EET) From: Anssi Hannula To: Mathias Nyman Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] xhci: fix garbage USBSTS being logged in some cases Date: Tue, 22 Feb 2022 15:41:16 +0200 Message-Id: <20220222134117.34844-1-anssi.hannula@bitwise.fi> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org xhci_decode_usbsts() is expected to return a zero-terminated string by its only caller, xhci_stop_endpoint_command_watchdog(), which directly logs the return value: xhci_warn(xhci, "USBSTS:%s\n", xhci_decode_usbsts(str, usbsts)); However, if no recognized bits are set in usbsts, the function will return without having called any sprintf() and therefore return an untouched non-zero-terminated caller-provided buffer, causing garbage to be output to log. Fix that by always including the raw value in the output. Note that before 4843b4b5ec64 ("xhci: fix even more unsafe memory usage in xhci tracing") the result effect in the failure case was different as a static buffer was used here, but the code still worked incorrectly. Fixes: 9c1aa36efdae ("xhci: Show host status when watchdog triggers and host is assumed dead.") Signed-off-by: Anssi Hannula --- Noticed this while debugging a USB issue. Let me know if you prefer a different fix. drivers/usb/host/xhci.h | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 8a0026ee9524..ac91647195f6 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -2642,6 +2642,7 @@ static inline const char *xhci_decode_usbsts(char *str, u32 usbsts) ret += sprintf(str + ret, " CNR"); if (usbsts & STS_HCE) ret += sprintf(str + ret, " HCE"); + ret += sprintf(str + ret, " (0x%08x)", usbsts); return str; }