From nobody Sat Sep 21 11:34:38 2024 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 2671CC433FE for ; Fri, 21 Oct 2022 02:17:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229920AbiJUCRv (ORCPT ); Thu, 20 Oct 2022 22:17:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229583AbiJUCRt (ORCPT ); Thu, 20 Oct 2022 22:17:49 -0400 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A9ED2303C2 for ; Thu, 20 Oct 2022 19:17:48 -0700 (PDT) Received: by mail-pl1-x62a.google.com with SMTP id f23so1038801plr.6 for ; Thu, 20 Oct 2022 19:17:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=RWiJ8t0XiMLAp749xvo/D5nNonOax/J4OCA0QCWYKPg=; b=IEomqwYECzTday/X19gn4iTn2ESEbePwdvwGUqdpq6cdaCnYL+2390UN6fCz+DZ4MO XJq39doIV27N1eDpO4pU7FjUjD/fa5mlKjLyuB/8BdkR9AFdB2IXcKf6FCN+gdc175lO CDzhzU2mdRnbUahKFkcZtCmOraLq4Dw1O1Q5LxqY01YwIDWlM4ilYb8ixhMkYmV3CCWt VyVfwUOgmodOmazNMgZe6HDjVirJxQQgYlXixkcwsVbxps7D2QuH3Li4ExzjYNdOQWjW AfMg4PaBAs3bL6f69l/nuj3igv0KyXjGbvXxyU41dWQqnIc5Gbe9pLgcRaMrVjVFA5ME 00GA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=RWiJ8t0XiMLAp749xvo/D5nNonOax/J4OCA0QCWYKPg=; b=YHt99EP1KJb2X0vl3cITwXuWolXUaYYrep1bePyJaJN47DquWqCAERsNlWEA1A9e1J +6g0+1y+/n3g+KrjNvr9fCUu26Vl1YOd1trE7QtfIN7q2YQsicV2LoURvkWGJsTRHked Dyy1sJo/oikTo3oJ5EkWZ06E81OIQwgnDKJ6ep32QrVjUyKZmNIOi3Cs+WYz9MUe5cys i5mv9ErkA5S9XKvTb0kZ6N7xEq01GpXPWhx86fI8bKq2CSkEuw100YBThB54jxJFTHEH O77p+bwSgmBihVwIoSzT/w6IK9PwXEM6B0Szoc2YBHGah5FWZ+IxANUvBI+yJiVXGv8b izlg== X-Gm-Message-State: ACrzQf3DJEkrqkmd2+9/N3HLMAVf/QdrS5C9NmJhsqfg137cXLRYX0yH mrJMx7AZk80loS3F/kdiyTk= X-Google-Smtp-Source: AMsMyM7VA6DBUk4v8CWsrLutpzNM9vktotatoow3OtSe49K0ega/rymrJe+ulbth7DHX6vMkOPyAWw== X-Received: by 2002:a17:90b:1649:b0:20d:2d96:6b05 with SMTP id il9-20020a17090b164900b0020d2d966b05mr55363430pjb.9.1666318667626; Thu, 20 Oct 2022 19:17:47 -0700 (PDT) Received: from localhost.localdomain ([2402:7500:577:b022:150a:a87e:ab3a:9736]) by smtp.gmail.com with ESMTPSA id q10-20020a631f4a000000b0045fcfde8263sm12021822pgm.53.2022.10.20.19.17.44 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 20 Oct 2022 19:17:46 -0700 (PDT) From: cy_huang To: lee@kernel.org, matthias.bgg@gmail.com Cc: chiaen_wu@richtek.com, andy.shevchenko@gmail.com, cy_huang@richtek.com, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] mfd: mt6370: Add the out-of-bound check to prevent the null pointer Date: Fri, 21 Oct 2022 10:17:41 +0800 Message-Id: <1666318661-11777-1-git-send-email-u0084500@gmail.com> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: ChiYuan Huang This potential risk could happen at regmap_raw_read() or regmap_raw_write() when accessing the over-bound register address. For testing, I try to reproduce it with a testing attribute file. Below's the issue trace log. [41.314358] pc : i2c_smbus_xfer+0x58/0x120 [41.314371] lr : i2c_smbus_read_i2c_block_data+0x74/0xc0 [41.399677] Call trace: [41.402153] i2c_smbus_xfer+0x58/0x120 [41.405956] i2c_smbus_read_i2c_block_data+0x74/0xc0 [41.410991] mt6370_regmap_read+0x40/0x60 [mt6370] [41.415855] _regmap_raw_read+0xe4/0x278 [41.419834] regmap_raw_read+0xec/0x240 [41.423721] rg_bound_show+0xb0/0x120 [mt6370] [41.428226] dev_attr_show+0x3c/0x80 [41.431851] sysfs_kf_seq_show+0xc4/0x150 [41.435916] kernfs_seq_show+0x48/0x60 [41.439718] seq_read_iter+0x11c/0x450 [41.443519] kernfs_fop_read_iter+0x124/0x1c0 [41.447937] vfs_read+0x1a8/0x288 [41.451296] ksys_read+0x74/0x100 [41.454654] __arm64_sys_read+0x24/0x30 [41.458541] invoke_syscall+0x54/0x118 [41.462344] el0_svc_common.constprop.4+0x94/0x128 [41.467202] do_el0_svc+0x3c/0xd0 [41.470562] el0_svc+0x20/0x60 [41.473658] el0t_64_sync_handler+0x94/0xb8 [41.477899] el0t_64_sync+0x15c/0x160 [41.481614] Code: 54000388 f9401262 aa1303e0 52800041 (f9400042) [41.487793] ---[ end trace 0000000000000000 ]--- Fixes: b2adf788e603 ("mfd: mt6370: Add MediaTek MT6370 support") Reported-by: Dan Carpenter Signed-off-by: ChiYuan Huang --- Dear reviewers: In v2, I refined the patch title and commit message. If there's still something improper, please kindly correct me. --- drivers/mfd/mt6370.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/mfd/mt6370.c b/drivers/mfd/mt6370.c index cf19cce..acbf960 100644 --- a/drivers/mfd/mt6370.c +++ b/drivers/mfd/mt6370.c @@ -190,6 +190,9 @@ static int mt6370_regmap_read(void *context, const void= *reg_buf, bank_idx =3D u8_buf[0]; bank_addr =3D u8_buf[1]; =20 + if (bank_idx >=3D MT6370_MAX_I2C) + return -EINVAL; + ret =3D i2c_smbus_read_i2c_block_data(info->i2c[bank_idx], bank_addr, val_size, val_buf); if (ret < 0) @@ -211,6 +214,9 @@ static int mt6370_regmap_write(void *context, const voi= d *data, size_t count) bank_idx =3D u8_buf[0]; bank_addr =3D u8_buf[1]; =20 + if (bank_idx >=3D MT6370_MAX_I2C) + return -EINVAL; + return i2c_smbus_write_i2c_block_data(info->i2c[bank_idx], bank_addr, len, data + MT6370_MAX_ADDRLEN); } --=20 2.7.4