Vulnerabilities > CVE-2021-47102 - Out-of-bounds Read vulnerability in Linux Kernel
Summary
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]
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Overread Buffers An adversary attacks a target by providing input that causes an application to read beyond the boundary of a defined buffer. This typically occurs when a value influencing where to start or stop reading is set to reflect positions outside of the valid memory location of the buffer. This type of attack may result in exposure of sensitive information, a system crash, or arbitrary code execution.