From patchwork Sun Jan 29 18:23:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe JAILLET X-Patchwork-Id: 13120195 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 005F9C05027 for ; Sun, 29 Jan 2023 18:23:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235274AbjA2SX2 (ORCPT ); Sun, 29 Jan 2023 13:23:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41040 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234784AbjA2SX1 (ORCPT ); Sun, 29 Jan 2023 13:23:27 -0500 Received: from smtp.smtpout.orange.fr (smtp-12.smtpout.orange.fr [80.12.242.12]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 213D21BAE8 for ; Sun, 29 Jan 2023 10:23:27 -0800 (PST) Received: from pop-os.home ([86.243.2.178]) by smtp.orange.fr with ESMTPA id MCKlpGwDQMaRbMCKmpnji1; Sun, 29 Jan 2023 19:23:25 +0100 X-ME-Helo: pop-os.home X-ME-Auth: Y2hyaXN0b3BoZS5qYWlsbGV0QHdhbmFkb28uZnI= X-ME-Date: Sun, 29 Jan 2023 19:23:25 +0100 X-ME-IP: 86.243.2.178 From: Christophe JAILLET To: gregkh@linuxfoundation.org, peterz@infradead.org, pmladek@suse.com, john.ogness@linutronix.de, baolu.lu@linux.intel.com, tglx@linutronix.de, mingo@kernel.org Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Christophe JAILLET Subject: [PATCH 1/3] usb: early: xhci-dbc: Fix a potential out-of-bound memory access Date: Sun, 29 Jan 2023 19:23:08 +0100 Message-Id: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org If xdbc_bulk_write() fails, the values in 'buf' can be anything. So the string is not guaranteed to be NULL terminated when xdbc_trace() is called. Reserve an extra byte, which will be zeroed automatically because 'buf' is a static variable, in order to avoid troubles, should it happen. Fixes: aeb9dd1de98c ("usb/early: Add driver for xhci debug capability") Signed-off-by: Christophe JAILLET --- drivers/usb/early/xhci-dbc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c index 797047154820..f3e23be227d4 100644 --- a/drivers/usb/early/xhci-dbc.c +++ b/drivers/usb/early/xhci-dbc.c @@ -874,7 +874,8 @@ static int xdbc_bulk_write(const char *bytes, int size) static void early_xdbc_write(struct console *con, const char *str, u32 n) { - static char buf[XDBC_MAX_PACKET]; + /* static variables are zeroed, so buf is always NULL terminated */ + static char buf[XDBC_MAX_PACKET + 1]; int chunk, ret; int use_cr = 0; From patchwork Sun Jan 29 18:23:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe JAILLET X-Patchwork-Id: 13120196 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 C27C4C636CC for ; Sun, 29 Jan 2023 18:23:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235294AbjA2SXm (ORCPT ); Sun, 29 Jan 2023 13:23:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41392 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235286AbjA2SXk (ORCPT ); Sun, 29 Jan 2023 13:23:40 -0500 Received: from smtp.smtpout.orange.fr (smtp-11.smtpout.orange.fr [80.12.242.11]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70AE81C329 for ; Sun, 29 Jan 2023 10:23:37 -0800 (PST) Received: from pop-os.home ([86.243.2.178]) by smtp.orange.fr with ESMTPA id MCKlpGwDQMaRbMCL1pnjjv; Sun, 29 Jan 2023 19:23:35 +0100 X-ME-Helo: pop-os.home X-ME-Auth: Y2hyaXN0b3BoZS5qYWlsbGV0QHdhbmFkb28uZnI= X-ME-Date: Sun, 29 Jan 2023 19:23:35 +0100 X-ME-IP: 86.243.2.178 From: Christophe JAILLET To: gregkh@linuxfoundation.org, peterz@infradead.org, pmladek@suse.com, john.ogness@linutronix.de, baolu.lu@linux.intel.com, tglx@linutronix.de, mingo@kernel.org Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Christophe JAILLET Subject: [PATCH 2/3] usb: early: xhci-dbc: Optimize early_xdbc_write() Date: Sun, 29 Jan 2023 19:23:09 +0100 Message-Id: <687bbcd940c59fbddd0e3a8b578fd3422962e50f.1675016180.git.christophe.jaillet@wanadoo.fr> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org There is no point in zeroing 'buf'. It would be cleared only once, and if the 'while' loop is executed several times, all but the first run would have a 'dirty' buffer. Moreover, the size of the chunk is computed in the loop and this size is passed to xdbc_bulk_write(). So remove this useless memset(). Signed-off-by: Christophe JAILLET --- Untested. --- drivers/usb/early/xhci-dbc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c index f3e23be227d4..965a24e47c0f 100644 --- a/drivers/usb/early/xhci-dbc.c +++ b/drivers/usb/early/xhci-dbc.c @@ -881,7 +881,7 @@ static void early_xdbc_write(struct console *con, const char *str, u32 n) if (!xdbc.xdbc_reg) return; - memset(buf, 0, XDBC_MAX_PACKET); + while (n > 0) { for (chunk = 0; chunk < XDBC_MAX_PACKET && n > 0; str++, chunk++, n--) { From patchwork Sun Jan 29 18:23:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe JAILLET X-Patchwork-Id: 13120207 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 17740C61D97 for ; Sun, 29 Jan 2023 18:23:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235315AbjA2SXs (ORCPT ); Sun, 29 Jan 2023 13:23:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41512 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235296AbjA2SXp (ORCPT ); Sun, 29 Jan 2023 13:23:45 -0500 Received: from smtp.smtpout.orange.fr (smtp-12.smtpout.orange.fr [80.12.242.12]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B2571C58D for ; Sun, 29 Jan 2023 10:23:40 -0800 (PST) Received: from pop-os.home ([86.243.2.178]) by smtp.orange.fr with ESMTPA id MCKlpGwDQMaRbMCL4pnjkG; Sun, 29 Jan 2023 19:23:38 +0100 X-ME-Helo: pop-os.home X-ME-Auth: Y2hyaXN0b3BoZS5qYWlsbGV0QHdhbmFkb28uZnI= X-ME-Date: Sun, 29 Jan 2023 19:23:38 +0100 X-ME-IP: 86.243.2.178 From: Christophe JAILLET To: gregkh@linuxfoundation.org, peterz@infradead.org, pmladek@suse.com, john.ogness@linutronix.de, baolu.lu@linux.intel.com, tglx@linutronix.de, mingo@kernel.org Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Christophe JAILLET Subject: [PATCH 3/3] usb: early: xhci-dbc: Use memcpy_and_pad() Date: Sun, 29 Jan 2023 19:23:10 +0100 Message-Id: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Instead of zeroing some memory and then copying data in part or all of it, use memcpy_and_pad(). This avoids writing some memory twice and should save a few cycles. Signed-off-by: Christophe JAILLET --- drivers/usb/early/xhci-dbc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c index 965a24e47c0f..341408410ed9 100644 --- a/drivers/usb/early/xhci-dbc.c +++ b/drivers/usb/early/xhci-dbc.c @@ -499,8 +499,7 @@ static int xdbc_bulk_transfer(void *data, int size, bool read) addr = xdbc.in_dma; xdbc.flags |= XDBC_FLAGS_IN_PROCESS; } else { - memset(xdbc.out_buf, 0, XDBC_MAX_PACKET); - memcpy(xdbc.out_buf, data, size); + memcpy_and_pad(xdbc.out_buf, XDBC_MAX_PACKET, data, size, 0); addr = xdbc.out_dma; xdbc.flags |= XDBC_FLAGS_OUT_PROCESS; }