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From:   Sven Peter <sven@svenpeter.dev>
To:     Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        Sven Peter <sven@svenpeter.dev>
Subject: [PATCH v2 2/3] usb: typec: tipd: Add an additional overflow check
Date:   Tue, 14 Sep 2021 16:02:34 +0200
Message-Id: <20210914140235.65955-2-sven@svenpeter.dev>
In-Reply-To: <20210914140235.65955-1-sven@svenpeter.dev>
References: <20210914140235.65955-1-sven@svenpeter.dev>
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tps6598x_block_read already checks for the maximum length of the read
but tps6598x_block_write does not. Add the symmetric check there as
well.

Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
v1 -> v2:
 - removed the WARN_ON to not crash machines running with panic-on-warn
   as pointed out by greg k-h

 drivers/usb/typec/tipd/core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
index c18ec3785592..8c79ba17a157 100644
--- a/drivers/usb/typec/tipd/core.c
+++ b/drivers/usb/typec/tipd/core.c
@@ -139,6 +139,9 @@ static int tps6598x_block_write(struct tps6598x *tps, u8 reg,
 {
 	u8 data[TPS_MAX_LEN + 1];
 
+	if (len + 1 > sizeof(data))
+		return -EINVAL;
+
 	if (!tps->i2c_protocol)
 		return regmap_raw_write(tps->regmap, reg, val, len);
 
-- 
2.25.1