From patchwork Fri Nov 26 16:47:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 1560263 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=112.213.38.117; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4J110B46Nyz9sR4 for ; Sat, 27 Nov 2021 03:48:26 +1100 (AEDT) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4J110B1FS4z3cC5 for ; 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Fri, 26 Nov 2021 17:48:11 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 2D17B8B781; Fri, 26 Nov 2021 17:48:11 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id 4YWlgfbD8PPb; Fri, 26 Nov 2021 17:48:11 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (unknown [192.168.204.6]) by messagerie.si.c-s.fr (Postfix) with ESMTP id C3D328B763; Fri, 26 Nov 2021 17:48:10 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (localhost [127.0.0.1]) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.16.1) with ESMTPS id 1AQGm0JW535496 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Fri, 26 Nov 2021 17:48:00 +0100 Received: (from chleroy@localhost) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.17.1/Submit) id 1AQGlwhX535494; Fri, 26 Nov 2021 17:47:58 +0100 X-Authentication-Warning: PO20335.IDSI0.si.c-s.fr: chleroy set sender to christophe.leroy@csgroup.eu using -f From: Christophe Leroy To: Evgeniy Polyakov , Greg Kroah-Hartman Subject: [PATCH v2] w1: Misuse of get_user()/put_user() reported by sparse Date: Fri, 26 Nov 2021 17:47:58 +0100 Message-Id: <926b572075a26835f4e39d05710cd1b75fd4d5a4.1637945194.git.christophe.leroy@csgroup.eu> X-Mailer: git-send-email 2.33.1 MIME-Version: 1.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1637945277; l=2705; s=20211009; h=from:subject:message-id; bh=SVUMkVnipXBjjq9DCo0mD5/KzMfOIiozrkaDhNORXKs=; b=juPaoguppVb32lY8pgYiub5+I7hjx7U5hpFro3lMp9EqeH7x70MekAOrY3fzVUtEFJ0MpZpzshNd 5cQ4vpG6AHZ7+FvY3pNlumwYLWG6vUiRzeraGWXVIX4otRjLA54n X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kernel test robot Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" sparse warnings: (new ones prefixed by >>) >> drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected char [noderef] __user *_pu_addr @@ got char *buf @@ drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: expected char [noderef] __user *_pu_addr drivers/w1/slaves/w1_ds28e04.c:342:13: sparse: got char *buf >> drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected char const [noderef] __user *_gu_addr @@ got char const *buf @@ drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: expected char const [noderef] __user *_gu_addr drivers/w1/slaves/w1_ds28e04.c:356:13: sparse: got char const *buf The buffer buf is a failsafe buffer in kernel space, it's not user memory hence doesn't deserve the use of get_user() or put_user(). Access 'buf' content directly. Reported-by: kernel test robot Link: https://lore.kernel.org/lkml/202111190526.K5vb7NWC-lkp@intel.com/T/ Signed-off-by: Christophe Leroy --- v2: Use sysfs_emit() and kstrtobool() --- drivers/w1/slaves/w1_ds28e04.c | 25 +++---------------------- 1 file changed, 3 insertions(+), 22 deletions(-) diff --git a/drivers/w1/slaves/w1_ds28e04.c b/drivers/w1/slaves/w1_ds28e04.c index e4f336111edc..98f80f412cfd 100644 --- a/drivers/w1/slaves/w1_ds28e04.c +++ b/drivers/w1/slaves/w1_ds28e04.c @@ -32,7 +32,7 @@ static int w1_strong_pullup = 1; module_param_named(strong_pullup, w1_strong_pullup, int, 0); /* enable/disable CRC checking on DS28E04-100 memory accesses */ -static char w1_enable_crccheck = 1; +static bool w1_enable_crccheck = true; #define W1_EEPROM_SIZE 512 #define W1_PAGE_COUNT 16 @@ -339,32 +339,13 @@ static BIN_ATTR_RW(pio, 1); static ssize_t crccheck_show(struct device *dev, struct device_attribute *attr, char *buf) { - if (put_user(w1_enable_crccheck + 0x30, buf)) - return -EFAULT; - - return sizeof(w1_enable_crccheck); + return sysfs_emit(buf, "%d\n", w1_enable_crccheck); } static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - char val; - - if (count != 1 || !buf) - return -EINVAL; - - if (get_user(val, buf)) - return -EFAULT; - - /* convert to decimal */ - val = val - 0x30; - if (val != 0 && val != 1) - return -EINVAL; - - /* set the new value */ - w1_enable_crccheck = val; - - return sizeof(w1_enable_crccheck); + return kstrtobool(buf, &w1_enable_crccheck) ? : count; } static DEVICE_ATTR_RW(crccheck);