CVE-2021-47102

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