From: Vincent Mailhol <mailhol.vincent@wanadoo.fr> mainline inclusion from mainline-v5.16-rc5 commit 94cddf1e9227a171b27292509d59691819c458db category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9S211 CVE: CVE-2021-47520 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- After calling netif_receive_skb(skb), dereferencing skb is unsafe. Especially, the can_frame cf which aliases skb memory is dereferenced just after the call netif_receive_skb(skb). Reordering the lines solves the issue. Fixes: b21d18b51b31 ("can: Topcliff: Add PCH_CAN driver.") Link: https://lore.kernel.org/all/20211123111654.621610-1-mailhol.vincent@wanadoo.... Cc: stable@vger.kernel.org Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- drivers/net/can/pch_can.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c index c1317889d3d8..ced11ea89269 100644 --- a/drivers/net/can/pch_can.c +++ b/drivers/net/can/pch_can.c @@ -703,11 +703,11 @@ static int pch_can_rx_normal(struct net_device *ndev, u32 obj_num, int quota) cf->data[i + 1] = data_reg >> 8; } - netif_receive_skb(skb); rcv_pkts++; stats->rx_packets++; quota--; stats->rx_bytes += cf->can_dlc; + netif_receive_skb(skb); pch_fifo_thresh(priv, obj_num); obj_num++; -- 2.34.1