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Date:   Tue, 30 Jul 2019 11:51:40 +0200
From:   Pavel Machek <pavel@denx.de>
To:     yoshihiro.shimoda.uh@renesas.com, kishon@ti.com,
        linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     cip-dev@lists.cip-project.org
Subject: phy-rcar-gen3-usb2: wrong parsing of role in role_store?
Message-ID: <20190730095140.GA29609@amd>
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Hi!

Code does strcmps, but does not actually check count. So AFAICT
writing "host-I-don't-want-I-need-peripheral" into the file will
succeed and turn it into host mode.

Also data beyond count in buf are going to be accessed.

Best regards,
								Pavel

static ssize_t role_store(struct device *dev, struct device_attribute *attr,
                          const char *buf, size_t count)
{
        struct rcar_gen3_chan *ch =3D dev_get_drvdata(dev);
        bool is_b_device;
        enum phy_mode cur_mode, new_mode;

        if (!ch->is_otg_channel || !rcar_gen3_is_any_rphy_initialized(ch))
                return -EIO;

        /* FIXME, this is wrong */
        if (!strncmp(buf, "host", strlen("host")))
                new_mode =3D PHY_MODE_USB_HOST;
        else if (!strncmp(buf, "peripheral", strlen("peripheral")))
                new_mode =3D PHY_MODE_USB_DEVICE;
        else
                return -EINVAL;


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