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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA3A1C3F6B0 for ; Fri, 29 Jul 2022 11:02:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235653AbiG2LCa (ORCPT ); Fri, 29 Jul 2022 07:02:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234581AbiG2LC2 (ORCPT ); Fri, 29 Jul 2022 07:02:28 -0400 Received: from mail-pj1-x102e.google.com (mail-pj1-x102e.google.com [IPv6:2607:f8b0:4864:20::102e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6EBF2AE34; Fri, 29 Jul 2022 04:02:27 -0700 (PDT) Received: by mail-pj1-x102e.google.com with SMTP id b10so4338902pjq.5; Fri, 29 Jul 2022 04:02:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=OVF3y7QB8gY+KNNuUfkiCKf/IXKM8mP2Ri70A+tABKc=; b=S0P3lwD3l+s1lvJSF8eRq3gpfq+aLEn+6Uni+I1V2pnk87kzSgK1TAq/curq5Br3hi DPtB7ok6on/MXaVwyQtsCeYiio9MBIBcSigERU5ltfpgHJQg6QqP1mdNhahTQXmHcgvi JoIQbv4Cg7ZhMLAKvlNso2MdGec/dJtdKCn6qL0834rIp5AVvrxiY5TdoFrxE4iFOEga jBVxSYTOwi3m0EQxUsaV22LL1jBXtapC76kmkKNDCVJCYqYdbD3pPfQ6vXPmgr4fqgMe nflkgeFdIhsxO4sV5j/LKGBcmkYX0IV0WvCcMK/vzmvlIvxSEqqmDELPdjUXBRll6sFD 6nLA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=OVF3y7QB8gY+KNNuUfkiCKf/IXKM8mP2Ri70A+tABKc=; b=cP2s3BXdOiZVDYivd0shs+dCdeUh3/ZAG+4RZ+C9lbZ07/x2KipXO02XYFmBnifKtx n/k+6FEhE/+y3BNiTwWzUOzrKGHl4HzX5aZxLSvFaLQ8Z055LgA0aq8exCDG/V21vfeh tHApCTSX4EPVl3xpZGPBQ+M/vBL9re24XWJR4PTQf/s1JS9k0218Ao6BKXrclKY2g5pR HJiWAKmddLqRTy1koTytrwywqiISbyUkGI7AZgjRnCGxz+3ATmg85+PchU9qpuiArejK ryLY4I3tHZAo3m9zLUSjGa8MK4qBWJX3125w8fM0j5rAbIB6RdPMT528oqWEBs1LMs2L Opgw== X-Gm-Message-State: ACgBeo32GeLnTb2NRK4I9YqOxJUN7GURj/bMPaTetjuUQrdDUG856y5U XM5tzub3A8F4Jl3qeEWx0g== X-Google-Smtp-Source: AA6agR6d/pXnMP5TH+WsFQflyu0AQvjGgMEEWwl8xZsEdBNSNUeR1i+IJtLFZ/mKEa1Apnu9uDWqPA== X-Received: by 2002:a17:90a:65cb:b0:1f2:4c5a:93e1 with SMTP id i11-20020a17090a65cb00b001f24c5a93e1mr3525406pjs.188.1659092547156; Fri, 29 Jul 2022 04:02:27 -0700 (PDT) Received: from localhost.localdomain ([166.111.133.51]) by smtp.gmail.com with ESMTPSA id t2-20020a17090a4e4200b001f22647cb56sm5528851pjl.27.2022.07.29.04.02.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 29 Jul 2022 04:02:26 -0700 (PDT) From: Zheyu Ma To: Seth Heasley , Neil Horman , Jean Delvare , Bill Brown , Wolfram Sang Cc: Zheyu Ma , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] i2c: ismt: Fix an out-of-bounds bug in ismt_access() Date: Fri, 29 Jul 2022 19:02:16 +0800 Message-Id: <20220729110216.557010-1-zheyuma97@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the driver does not check the data from the user, the variable 'data->block[0]' may be very large to cause an out-of-bounds bug. The following log can reveal it: [ 33.995542] i2c i2c-1: ioctl, cmd=0x720, arg=0x7ffcb3dc3a20 [ 33.995978] ismt_smbus 0000:00:05.0: I2C_SMBUS_BLOCK_DATA: WRITE [ 33.996475] ================================================================== [ 33.996995] BUG: KASAN: out-of-bounds in ismt_access.cold+0x374/0x214b [ 33.997473] Read of size 18446744073709551615 at addr ffff88810efcfdb1 by task ismt_poc/485 [ 33.999450] Call Trace: [ 34.001849] memcpy+0x20/0x60 [ 34.002077] ismt_access.cold+0x374/0x214b [ 34.003382] __i2c_smbus_xfer+0x44f/0xfb0 [ 34.004007] i2c_smbus_xfer+0x10a/0x390 [ 34.004291] i2cdev_ioctl_smbus+0x2c8/0x710 [ 34.005196] i2cdev_ioctl+0x5ec/0x74c Fix this bug by checking the size of 'data->block[0]' first. Fixes: 13f35ac14cd0 ("i2c: Adding support for Intel iSMT SMBus 2.0 host controller") Signed-off-by: Zheyu Ma --- drivers/i2c/busses/i2c-ismt.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/i2c/busses/i2c-ismt.c b/drivers/i2c/busses/i2c-ismt.c index 6078fa0c0d48..63120c41354c 100644 --- a/drivers/i2c/busses/i2c-ismt.c +++ b/drivers/i2c/busses/i2c-ismt.c @@ -509,6 +509,9 @@ static int ismt_access(struct i2c_adapter *adap, u16 addr, if (read_write == I2C_SMBUS_WRITE) { /* Block Write */ dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: WRITE\n"); + if (data->block[0] < 1 || data->block[0] > I2C_SMBUS_BLOCK_MAX) + return -EINVAL; + dma_size = data->block[0] + 1; dma_direction = DMA_TO_DEVICE; desc->wr_len_cmd = dma_size; -- 2.25.1