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| author | Pavel Skripkin <paskripkin@gmail.com> | 2021-06-17 21:51:30 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-14 17:59:01 +0300 |
| commit | 0f7f0b917d881967682aba1bd973f1a6d2168e91 (patch) | |
| tree | 745310eb0aef3edd4a8f13338c984c92e79b628a | |
| parent | 4d294f705293149279910f503a43fc7a5e9eca5a (diff) | |
| download | linux-0f7f0b917d881967682aba1bd973f1a6d2168e91.tar.xz | |
net: can: ems_usb: fix use-after-free in ems_usb_disconnect()
commit ab4a0b8fcb9a95c02909b62049811bd2e586aaa4 upstream.
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 <stable@vger.kernel.org>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/net/can/usb/ems_usb.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c index 18f40eb20360..5cd26c1b78ad 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); } } |