From ab4a0b8fcb9a95c02909b62049811bd2e586aaa4 Mon Sep 17 00:00:00 2001 From: Pavel Skripkin Date: Thu, 17 Jun 2021 21:51:30 +0300 Subject: net: can: ems_usb: fix use-after-free in ems_usb_disconnect() In ems_usb_disconnect() dev pointer, which is netdev private data, is used after free_candev() call: | if (dev) { | unregister_netdev(dev->netdev); | free_candev(dev->netdev); | | unlink_all_urbs(dev); | | usb_free_urb(dev->intr_urb); | | kfree(dev->intr_in_buffer); | kfree(dev->tx_msg_buffer); | } Fix it by simply moving free_candev() at the end of the block. Fail log: | BUG: KASAN: use-after-free in ems_usb_disconnect | Read of size 8 at addr ffff88804e041008 by task kworker/1:2/2895 | | CPU: 1 PID: 2895 Comm: kworker/1:2 Not tainted 5.13.0-rc5+ #164 | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a-rebuilt.opensuse.4 | Workqueue: usb_hub_wq hub_event | Call Trace: | dump_stack (lib/dump_stack.c:122) | print_address_description.constprop.0.cold (mm/kasan/report.c:234) | kasan_report.cold (mm/kasan/report.c:420 mm/kasan/report.c:436) | ems_usb_disconnect (drivers/net/can/usb/ems_usb.c:683 drivers/net/can/usb/ems_usb.c:1058) Fixes: 702171adeed3 ("ems_usb: Added support for EMS CPC-USB/ARM7 CAN/USB interface") Link: https://lore.kernel.org/r/20210617185130.5834-1-paskripkin@gmail.com Cc: linux-stable Signed-off-by: Pavel Skripkin Signed-off-by: Marc Kleine-Budde --- drivers/net/can/usb/ems_usb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/net/can') diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c index 5af69787d9d5..0a37af4a3fa4 100644 --- a/drivers/net/can/usb/ems_usb.c +++ b/drivers/net/can/usb/ems_usb.c @@ -1053,7 +1053,6 @@ static void ems_usb_disconnect(struct usb_interface *intf) if (dev) { unregister_netdev(dev->netdev); - free_candev(dev->netdev); unlink_all_urbs(dev); @@ -1061,6 +1060,8 @@ static void ems_usb_disconnect(struct usb_interface *intf) kfree(dev->intr_in_buffer); kfree(dev->tx_msg_buffer); + + free_candev(dev->netdev); } } -- cgit v1.2.3 From b17233d385d0b6b43ecf81d43008cb1bbb008166 Mon Sep 17 00:00:00 2001 From: Stephane Grosjean Date: Wed, 23 Jun 2021 16:26:00 +0200 Subject: can: peak_pciefd: pucan_handle_status(): fix a potential starvation issue in TX path Rather than just indicating that transmission can start, this patch requires the explicit flushing of the network TX queue when the driver is informed by the device that it can transmit, next to its configuration. In this way, if frames have already been written by the application, they will actually be transmitted. Fixes: ffd137f7043c ("can: peak/pcie_fd: remove useless code when interface starts") Link: https://lore.kernel.org/r/20210623142600.149904-1-s.grosjean@peak-system.com Cc: linux-stable Signed-off-by: Stephane Grosjean Signed-off-by: Marc Kleine-Budde --- drivers/net/can/peak_canfd/peak_canfd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/net/can') diff --git a/drivers/net/can/peak_canfd/peak_canfd.c b/drivers/net/can/peak_canfd/peak_canfd.c index 00847cbaf7b6..d08718e98e11 100644 --- a/drivers/net/can/peak_canfd/peak_canfd.c +++ b/drivers/net/can/peak_canfd/peak_canfd.c @@ -351,8 +351,8 @@ static int pucan_handle_status(struct peak_canfd_priv *priv, return err; } - /* start network queue (echo_skb array is empty) */ - netif_start_queue(ndev); + /* wake network queue up (echo_skb array is empty) */ + netif_wake_queue(ndev); return 0; } -- cgit v1.2.3