From patchwork Fri Oct 21 02:17:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: ChiYuan Huang X-Patchwork-Id: 13014196 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 73F8EC433FE for ; Fri, 21 Oct 2022 02:18:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date:Subject:Cc:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=euFPHyRjZiueSDB8HJdNGgIWGsios1XPxHHt9Liosaw=; b=xPljRrvgz6EFAV jOBNH+/ll7E95LoC2c8G/82M4JZ5kLBsgoeSbocmnydQS+jZxkgw/03l2hJSdwCv+/5OJMBe4E9pU DnF3/sL1tstMWEgBcn4EX+3Omhs/WaCzsGyEJ7WAkqrGGrALoNWuVxtepYh8fo7bVqWKgmlhwWixi MzmUMFF48WNVhahLIJEKxmK01ZvkPFbNGo9ka15lE+CLIp/k3ua07JsuBXFNbd7FP78vG/azAqlcI fBDDe23TJpYzMieVbk6XnuwYfDL08/nK1fuQxn0m0dHL7QNmBA6LCsmimKDdj3R09uVl3DiRwD5vu isMmH+S6rlxICBb7gs5w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1olhbd-004Nls-La; Fri, 21 Oct 2022 02:17:53 +0000 Received: from mail-pl1-x632.google.com ([2607:f8b0:4864:20::632]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1olhba-004NkB-4a; Fri, 21 Oct 2022 02:17:51 +0000 Received: by mail-pl1-x632.google.com with SMTP id y4so1055983plb.2; 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=z7YMAs8QU49ooBZjaOIWbfYALgWMYZcSk6rl8ZhiIiLVSwqaFwP4J+R0zexFRze9VF erLn40WBBPTHG1ofzXK34c2T86ng6ro8CrwYyH7iTmwDhS0H9pnlDW7iPId5txW0SK0Q n1WZVrZRnP/tivp0aRaaRlmJWLydlvHp8YG0CEUr/yAxThlaRY/l82C5oLPuf6nGOiVR mWQIqcJzXkUiN+I1EwRoLafQ+vh9x0Hqp/+ck+eOL6x/0eIyxq5a0KuCEIETdU4dMGEs q3V0WyvmmrB+90fy7PuhdWtiOxCQrS6zws8IKfHfRmPbw5RjphnDAyiTbU7n+RU1ftSQ QEUA== X-Gm-Message-State: ACrzQf1DRdYlKuzrxewrZ+2M+3eJ79veWwjJpIpGeX8R4KbjnbHaDq+4 UjDMUrdPhfkpMA+0BV04aA5J1OKJLKw= 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221020_191750_258661_5DAAB74C X-CRM114-Status: GOOD ( 12.35 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 = u8_buf[0]; bank_addr = u8_buf[1]; + if (bank_idx >= MT6370_MAX_I2C) + return -EINVAL; + ret = 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 void *data, size_t count) bank_idx = u8_buf[0]; bank_addr = u8_buf[1]; + if (bank_idx >= MT6370_MAX_I2C) + return -EINVAL; + return i2c_smbus_write_i2c_block_data(info->i2c[bank_idx], bank_addr, len, data + MT6370_MAX_ADDRLEN); }