From 50aca891d7a554db0901b245167cd653d73aaa71 Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Wed, 20 Jan 2021 20:41:37 +0900 Subject: [PATCH] can: peak_usb: fix use after free bugs After calling peak_usb_netif_rx_ni(skb), dereferencing skb is unsafe. Especially, the can_frame cf which aliases skb memory is accessed after the peak_usb_netif_rx_ni(). Reordering the lines solves the issue. Fixes: 0a25e1f4f185 ("can: peak_usb: add support for PEAK new CANFD USB adapters") Link: https://lore.kernel.org/r/20210120114137.200019-4-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol Signed-off-by: Marc Kleine-Budde --- drivers/net/can/usb/peak_usb/pcan_usb_fd.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c index 61631f4fd92a..f347ecc79aef 100644 --- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c +++ b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c @@ -514,11 +514,11 @@ static int pcan_usb_fd_decode_canmsg(struct pcan_usb_fd_if *usb_if, else memcpy(cfd->data, rm->d, cfd->len); - peak_usb_netif_rx(skb, &usb_if->time_ref, le32_to_cpu(rm->ts_low)); - netdev->stats.rx_packets++; netdev->stats.rx_bytes += cfd->len; + peak_usb_netif_rx(skb, &usb_if->time_ref, le32_to_cpu(rm->ts_low)); + return 0; } @@ -580,11 +580,11 @@ static int pcan_usb_fd_decode_status(struct pcan_usb_fd_if *usb_if, if (!skb) return -ENOMEM; - peak_usb_netif_rx(skb, &usb_if->time_ref, le32_to_cpu(sm->ts_low)); - netdev->stats.rx_packets++; netdev->stats.rx_bytes += cf->len; + peak_usb_netif_rx(skb, &usb_if->time_ref, le32_to_cpu(sm->ts_low)); + return 0; }