From mboxrd@z Thu Jan 1 00:00:00 1970 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 2927BC55186 for ; Wed, 22 Apr 2020 10:27:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 053FC208E4 for ; Wed, 22 Apr 2020 10:27:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587551248; bh=gBGl2Mpr3gMecv69cjvXn7IuOzZ3+xBLzvfmu0V5t70=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kB3MHDTHZ9x4mis/rnwuuxYOy7BNvlEkaKjHpF/hOhboXXIbUMN7/Z0h0ZsO7NyrM xxjMMrggmziRAtqqQ4S7J7BhCmfXT1ThonpP0eNXXOS6GaO2FhwbKsXBJtqoshPVww naBm0MpaY1u79vZwMlbBjj4t1MPkX3CWb4F0x6F8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730879AbgDVK10 (ORCPT ); Wed, 22 Apr 2020 06:27:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:36280 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730849AbgDVK1S (ORCPT ); Wed, 22 Apr 2020 06:27:18 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5B9B320784; Wed, 22 Apr 2020 10:27:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587551236; bh=gBGl2Mpr3gMecv69cjvXn7IuOzZ3+xBLzvfmu0V5t70=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EheM5fU1QZkwz5rZOnKtYcHC1vrI2vQa4rhVj9qxt0Gmid5CaZ53CJL926CTE0LIn /A5Z//ROfxd/SKqBP2dpVKroFpEyXkdR7nAeJQ5hiyDf+Hhvn60Cj66t/sZGXyzh/1 j2eOiWrfmA7d6Ijx/h+/k4sNpe7caY6LJqtv1cpw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stephen Rothwell , Laurentiu Tudor , Michael Ellerman Subject: [PATCH 5.6 154/166] tty: evh_bytechan: Fix out of bounds accesses Date: Wed, 22 Apr 2020 11:58:01 +0200 Message-Id: <20200422095105.030657420@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095047.669225321@linuxfoundation.org> References: <20200422095047.669225321@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stephen Rothwell commit 3670664b5da555a2a481449b3baafff113b0ac35 upstream. ev_byte_channel_send() assumes that its third argument is a 16 byte array. Some places where it is called it may not be (or we can't easily tell if it is). Newer compilers have started producing warnings about this, so make sure we actually pass a 16 byte array. There may be more elegant solutions to this, but the driver is quite old and hasn't been updated in many years. The warnings (from a powerpc allyesconfig build) are: In file included from include/linux/byteorder/big_endian.h:5, from arch/powerpc/include/uapi/asm/byteorder.h:14, from include/asm-generic/bitops/le.h:6, from arch/powerpc/include/asm/bitops.h:250, from include/linux/bitops.h:29, from include/linux/kernel.h:12, from include/asm-generic/bug.h:19, from arch/powerpc/include/asm/bug.h:109, from include/linux/bug.h:5, from include/linux/mmdebug.h:5, from include/linux/gfp.h:5, from include/linux/slab.h:15, from drivers/tty/ehv_bytechan.c:24: drivers/tty/ehv_bytechan.c: In function ‘ehv_bc_udbg_putc’: arch/powerpc/include/asm/epapr_hcalls.h:298:20: warning: array subscript 1 is outside array bounds of ‘const char[1]’ [-Warray-bounds] 298 | r6 = be32_to_cpu(p[1]); include/uapi/linux/byteorder/big_endian.h:40:51: note: in definition of macro ‘__be32_to_cpu’ 40 | #define __be32_to_cpu(x) ((__force __u32)(__be32)(x)) | ^ arch/powerpc/include/asm/epapr_hcalls.h:298:7: note: in expansion of macro ‘be32_to_cpu’ 298 | r6 = be32_to_cpu(p[1]); | ^~~~~~~~~~~ drivers/tty/ehv_bytechan.c:166:13: note: while referencing ‘data’ 166 | static void ehv_bc_udbg_putc(char c) | ^~~~~~~~~~~~~~~~ Fixes: dcd83aaff1c8 ("tty/powerpc: introduce the ePAPR embedded hypervisor byte channel driver") Signed-off-by: Stephen Rothwell Tested-by: Laurentiu Tudor [mpe: Trim warnings from change log] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200109183912.5fcb52aa@canb.auug.org.au Signed-off-by: Greg Kroah-Hartman --- drivers/tty/ehv_bytechan.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) --- a/drivers/tty/ehv_bytechan.c +++ b/drivers/tty/ehv_bytechan.c @@ -136,6 +136,21 @@ static int find_console_handle(void) return 1; } +static unsigned int local_ev_byte_channel_send(unsigned int handle, + unsigned int *count, + const char *p) +{ + char buffer[EV_BYTE_CHANNEL_MAX_BYTES]; + unsigned int c = *count; + + if (c < sizeof(buffer)) { + memcpy(buffer, p, c); + memset(&buffer[c], 0, sizeof(buffer) - c); + p = buffer; + } + return ev_byte_channel_send(handle, count, p); +} + /*************************** EARLY CONSOLE DRIVER ***************************/ #ifdef CONFIG_PPC_EARLY_DEBUG_EHV_BC @@ -154,7 +169,7 @@ static void byte_channel_spin_send(const do { count = 1; - ret = ev_byte_channel_send(CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE, + ret = local_ev_byte_channel_send(CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE, &count, &data); } while (ret == EV_EAGAIN); } @@ -221,7 +236,7 @@ static int ehv_bc_console_byte_channel_s while (count) { len = min_t(unsigned int, count, EV_BYTE_CHANNEL_MAX_BYTES); do { - ret = ev_byte_channel_send(handle, &len, s); + ret = local_ev_byte_channel_send(handle, &len, s); } while (ret == EV_EAGAIN); count -= len; s += len; @@ -401,7 +416,7 @@ static void ehv_bc_tx_dequeue(struct ehv CIRC_CNT_TO_END(bc->head, bc->tail, BUF_SIZE), EV_BYTE_CHANNEL_MAX_BYTES); - ret = ev_byte_channel_send(bc->handle, &len, bc->buf + bc->tail); + ret = local_ev_byte_channel_send(bc->handle, &len, bc->buf + bc->tail); /* 'len' is valid only if the return code is 0 or EV_EAGAIN */ if (!ret || (ret == EV_EAGAIN))