CVE-2021-47102

In the Linux kernel, the following vulnerability has been resolved: net:
marvell: prestera: fix incorrect structure access In line: upper =
info->upper_dev; We access upper_dev field, which is related only for
particular events (e.g. event == NETDEV_CHANGEUPPER). So, this line cause
invalid memory access for another events, when ptr is not
netdev_notifier_changeupper_info. The KASAN logs are as follows: [
30.123165] BUG: KASAN: stack-out-of-bounds in
prestera_netdev_port_event.constprop.0+0x68/0x538 [prestera] [ 30.133336]
Read of size 8 at addr ffff80000cf772b0 by task udevd/778 [ 30.139866] [
30.141398] CPU: 0 PID: 778 Comm: udevd Not tainted 5.16.0-rc3 #6 [
30.147588] Hardware name: DNI AmazonGo1 A7040 board (DT) [ 30.153056] Call
trace: [ 30.155547] dump_backtrace+0x0/0x2c0 [ 30.159320]
show_stack+0x18/0x30 [ 30.162729] dump_stack_lvl+0x68/0x84 [ 30.166491]
print_address_description.constprop.0+0x74/0x2b8 [ 30.172346]
kasan_report+0x1e8/0x250 [ 30.176102] __asan_load8+0x98/0xe0 [ 30.179682]
prestera_netdev_port_event.constprop.0+0x68/0x538 [prestera] [ 30.186847]
prestera_netdev_event_handler+0x1b4/0x1c0 [prestera] [ 30.193313]
raw_notifier_call_chain+0x74/0xa0 [ 30.197860]
call_netdevice_notifiers_info+0x68/0xc0 [ 30.202924]
register_netdevice+0x3cc/0x760 [ 30.207190] register_netdev+0x24/0x50 [
30.211015] prestera_device_register+0x8a0/0xba0 [prestera]