From patchwork Sun Mar 15 09:34:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Takashi Iwai X-Patchwork-Id: 222487 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1415C2BB1D for ; Sun, 15 Mar 2020 09:35:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D34A3206BE for ; Sun, 15 Mar 2020 09:35:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728164AbgCOJfJ (ORCPT ); Sun, 15 Mar 2020 05:35:09 -0400 Received: from mx2.suse.de ([195.135.220.15]:57088 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728133AbgCOJfJ (ORCPT ); Sun, 15 Mar 2020 05:35:09 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 81F86ABD7; Sun, 15 Mar 2020 09:35:07 +0000 (UTC) From: Takashi Iwai To: netdev@vger.kernel.org Cc: "David S . Miller" Subject: [PATCH v2 1/6] net: caif: Use scnprintf() for avoiding potential buffer overflow Date: Sun, 15 Mar 2020 10:34:58 +0100 Message-Id: <20200315093503.8558-2-tiwai@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200315093503.8558-1-tiwai@suse.de> References: <20200315093503.8558-1-tiwai@suse.de> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Since snprintf() returns the would-be-output size instead of the actual output size, the succeeding calls may go beyond the given buffer limit. Fix it by replacing with scnprintf(). Cc: "David S . Miller" Cc: netdev@vger.kernel.org Signed-off-by: Takashi Iwai --- v1->v2: Align the remaining lines to the open parenthesis drivers/net/caif/caif_spi.c | 72 ++++++++++++++++++++++----------------------- 1 file changed, 36 insertions(+), 36 deletions(-) diff --git a/drivers/net/caif/caif_spi.c b/drivers/net/caif/caif_spi.c index 8e81bdf98ac6..63f2548f5b1b 100644 --- a/drivers/net/caif/caif_spi.c +++ b/drivers/net/caif/caif_spi.c @@ -141,29 +141,29 @@ static ssize_t dbgfs_state(struct file *file, char __user *user_buf, return 0; /* Print out debug information. */ - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "CAIF SPI debug information:\n"); - - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), FLAVOR); - - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "STATE: %d\n", cfspi->dbg_state); - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "Previous CMD: 0x%x\n", cfspi->pcmd); - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "Current CMD: 0x%x\n", cfspi->cmd); - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "Previous TX len: %d\n", cfspi->tx_ppck_len); - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "Previous RX len: %d\n", cfspi->rx_ppck_len); - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "Current TX len: %d\n", cfspi->tx_cpck_len); - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "Current RX len: %d\n", cfspi->rx_cpck_len); - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "Next TX len: %d\n", cfspi->tx_npck_len); - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "Next RX len: %d\n", cfspi->rx_npck_len); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "CAIF SPI debug information:\n"); + + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), FLAVOR); + + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "STATE: %d\n", cfspi->dbg_state); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "Previous CMD: 0x%x\n", cfspi->pcmd); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "Current CMD: 0x%x\n", cfspi->cmd); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "Previous TX len: %d\n", cfspi->tx_ppck_len); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "Previous RX len: %d\n", cfspi->rx_ppck_len); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "Current TX len: %d\n", cfspi->tx_cpck_len); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "Current RX len: %d\n", cfspi->rx_cpck_len); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "Next TX len: %d\n", cfspi->tx_npck_len); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "Next RX len: %d\n", cfspi->rx_npck_len); if (len > DEBUGFS_BUF_SIZE) len = DEBUGFS_BUF_SIZE; @@ -180,23 +180,23 @@ static ssize_t print_frame(char *buf, size_t size, char *frm, int len = 0; int i; for (i = 0; i < count; i++) { - len += snprintf((buf + len), (size - len), + len += scnprintf((buf + len), (size - len), "[0x" BYTE_HEX_FMT "]", frm[i]); if ((i == cut) && (count > (cut * 2))) { /* Fast forward. */ i = count - cut; - len += snprintf((buf + len), (size - len), - "--- %zu bytes skipped ---\n", - count - (cut * 2)); + len += scnprintf((buf + len), (size - len), + "--- %zu bytes skipped ---\n", + count - (cut * 2)); } if ((!(i % 10)) && i) { - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "\n"); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "\n"); } } - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), "\n"); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), "\n"); return len; } @@ -214,18 +214,18 @@ static ssize_t dbgfs_frame(struct file *file, char __user *user_buf, return 0; /* Print out debug information. */ - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "Current frame:\n"); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "Current frame:\n"); - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "Tx data (Len: %d):\n", cfspi->tx_cpck_len); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "Tx data (Len: %d):\n", cfspi->tx_cpck_len); len += print_frame((buf + len), (DEBUGFS_BUF_SIZE - len), cfspi->xfer.va_tx[0], (cfspi->tx_cpck_len + SPI_CMD_SZ), 100); - len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), - "Rx data (Len: %d):\n", cfspi->rx_cpck_len); + len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), + "Rx data (Len: %d):\n", cfspi->rx_cpck_len); len += print_frame((buf + len), (DEBUGFS_BUF_SIZE - len), cfspi->xfer.va_rx,