From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: [PATCH 15/20] can: dev: __can_get_echo_skb(): Don't crash the kernel if can_priv::echo_skb is accessed out of bounds Date: Mon, 12 Nov 2018 12:57:23 +0100 Message-ID: <20181112115728.18331-16-mkl@pengutronix.de> References: <20181112115728.18331-1-mkl@pengutronix.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20181112115728.18331-1-mkl@pengutronix.de> Sender: stable-owner@vger.kernel.org To: netdev@vger.kernel.org Cc: davem@davemloft.net, linux-can@vger.kernel.org, kernel@pengutronix.de, Marc Kleine-Budde , linux-stable List-Id: linux-can.vger.kernel.org If the "struct can_priv::echo_skb" is accessed out of bounds would lead to a kernel crash. Better print a sensible warning message instead and try to recover. Cc: linux-stable Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c index 46cc5fec4043..c05e4d50d43d 100644 --- a/drivers/net/can/dev.c +++ b/drivers/net/can/dev.c @@ -481,7 +481,11 @@ struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 { struct can_priv *priv = netdev_priv(dev); - BUG_ON(idx >= priv->echo_skb_max); + if (idx >= priv->echo_skb_max) { + netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n", + __func__, idx, priv->echo_skb_max); + return NULL; + } if (priv->echo_skb[idx]) { /* Using "struct canfd_frame::len" for the frame -- 2.19.1