Commit 31cb32a5 authored by Vincent Mailhol's avatar Vincent Mailhol Committed by Marc Kleine-Budde
Browse files

can: m_can: m_can_read_fifo: fix memory leak in error branch 

In m_can_read_fifo(), if the second call to m_can_fifo_read() fails,
the function jump to the out_fail label and returns without calling
m_can_receive_skb(). This means that the skb previously allocated by
alloc_can_skb() is not freed. In other terms, this is a memory leak.

This patch adds a goto label to destroy the skb if an error occurs.

Issue was found with GCC -fanalyzer, please follow the link below for
details.

Fixes: e3938177 ("can: m_can: Disable IRQs on FIFO bus errors")
Link: https://lore.kernel.org/all/20211107050755.70655-1-mailhol.vincent@wanadoo.fr


Cc: stable@vger.kernel.org
Cc: Matt Kline <matt@bitbashing.io>
Signed-off-by: default avatarVincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent f58ac1ad

drivers/net/can/m_can/m_can.c

+3 −1
Original line number Diff line number Diff line
@@ -517,7 +517,7 @@ static int m_can_read_fifo(struct net_device *dev, u32 rxfs) 
		err = m_can_fifo_read(cdev, fgi, M_CAN_FIFO_DATA,

				      cf->data, DIV_ROUND_UP(cf->len, 4));

		if (err)

			goto out_fail;

			goto out_free_skb;

	}



	/* acknowledge rx fifo 0 */
@@ -532,6 +532,8 @@ static int m_can_read_fifo(struct net_device *dev, u32 rxfs) 


	return 0;



out_free_skb:

	kfree_skb(skb);

out_fail:

	netdev_err(dev, "FIFO read returned %d\n", err);

	return err;