From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x2254icRZoqELjm2JKN0saNRBFRUBn5iZWZvMr9zxokMbCeQ9F3MiNr20CZMFrt0ZkGfqPtSV ARC-Seal: i=1; a=rsa-sha256; t=1516748040; cv=none; d=google.com; s=arc-20160816; b=ZYe+be9AGG8f7TN99C+lScGybYZsH/EGFjLtuYA9sTFZnsRzrJpEHiWz5jeEFg5q60 J+JScJOG8D3hxcpQAAHHWNPsc/xRnmOhgAdUxBbgxma8ml0YeG5QR1nv9XAos0t7891a /L487gLyVI7eDwqP8oxf5aEsDSdAfXIeGEtMbjxIrjh/zxnVIWND02pTeug42Zo+kn9A 5RAFUUuBJWEdcpLM6xS8FUI3rwBp/Oc73abTutsMKY3yo4L7BSWyad58Rvwt/zOdPvbY ZpVeMYbCEiw6MaR4lPrSKjyNG9a5xRgWCUL3imCNZi0V4zurG4pa5kNH7kgtr9OE87uX nIEQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:arc-authentication-results; bh=umUptfHq03yScNSIUYqrFwP1JSwsqNCqQ/gkr0brykM=; b=NnqZpyA5xdrLHfomsJnaXPu5Q6EUO5Cm76yddkpqHw51jwE4qViO4qmsN1ZNCH7qVz X0U1gTiTvO+9Vw/IjkavTllkCTO7T6onGynMEudFH83xeBoHGDLiwUtV8kdr6Jce6lpj bIv1YRTGys6TlysNtmj2c/Igv0jpIa/0KeoI9SJm5J/DmQwOswBtVuBQum2B+OudoqQT 9sWuMGMbLXdyN1eETDwbbMYBRgQkAaDYthOmFr4W5wksszShNLvlak9LKt0Ojxpqn/7i MIg4WAO8Y/n9flfULJI9le3mE5C0km1K514vKRDCcgH+FxRGz4fZ83kPlSM2K/yZpX3P oJOA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@lechnology.com header.s=default header.b=r4QWm63k; spf=pass (google.com: domain of david@lechnology.com designates 206.190.152.46 as permitted sender) smtp.mailfrom=david@lechnology.com Authentication-Results: mx.google.com; dkim=pass header.i=@lechnology.com header.s=default header.b=r4QWm63k; spf=pass (google.com: domain of david@lechnology.com designates 206.190.152.46 as permitted sender) smtp.mailfrom=david@lechnology.com From: David Lechner To: linux-kernel@vger.kernel.org Cc: David Lechner , Mark Brown , Greg Kroah-Hartman Subject: [PATCH 1/2] regmap: fix NULL pointer dereference in regmap_name_read_file() Date: Tue, 23 Jan 2018 16:53:42 -0600 Message-Id: <1516748023-17235-2-git-send-email-david@lechnology.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1516748023-17235-1-git-send-email-david@lechnology.com> References: <1516748023-17235-1-git-send-email-david@lechnology.com> X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - vern.gendns.com X-AntiAbuse: Original Domain - linuxfoundation.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - lechnology.com X-Get-Message-Sender-Via: vern.gendns.com: authenticated_id: davidmain+lechnology.com/only user confirmed/virtual account not confirmed X-Authenticated-Sender: vern.gendns.com: davidmain@lechnology.com X-Source: X-Source-Args: X-Source-Dir: X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1590425592886901979?= X-GMAIL-MSGID: =?utf-8?q?1590425592886901979?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: This fixes a possible NULL pointer dereference oops in regmap_name_read_file() when the regmap does not have a device associated with it. Signed-off-by: David Lechner --- drivers/base/regmap/regmap-debugfs.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c index 36ce351..0df7379 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -40,6 +40,7 @@ static ssize_t regmap_name_read_file(struct file *file, loff_t *ppos) { struct regmap *map = file->private_data; + const char *name = NULL; int ret; char *buf; @@ -47,7 +48,10 @@ static ssize_t regmap_name_read_file(struct file *file, if (!buf) return -ENOMEM; - ret = snprintf(buf, PAGE_SIZE, "%s\n", map->dev->driver->name); + if (map->dev && map->dev->driver) + name = map->dev->driver->name; + + ret = snprintf(buf, PAGE_SIZE, "%s\n", name); if (ret < 0) { kfree(buf); return ret; -- 2.7.4