From 31cb32a590d62b18f69a9a6d433f4e69c74fdd56 Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Sun, 7 Nov 2021 14:07:55 +0900 Subject: [PATCH] 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: e39381770ec9 ("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 Signed-off-by: Vincent Mailhol Signed-off-by: Marc Kleine-Budde --- drivers/net/can/m_can/m_can.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index 91be87c4f4d3..e330b4c121bf 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -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;