---
id: CVE-2021-47102
title: "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: marvell: prestera: fix incorrect structure access\n\nIn line:\n\tupper = info->upper_dev;\nWe access upper_dev field, which is related only for particular events\n(e.g"
summary: "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: marvell: prestera: fix incorrect structure access\n\nIn line:\n\tupper = info->upper_dev;\nWe access upper_dev field, which is related only for particular events\n(e.g. …"
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'
cwe:
  - CWE-125
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.14, < 5.15.12'
  - linux_kernel = 5.16
patched:
  - linux_kernel 5.15.12
published: '2024-03-04'
updated: '2026-08-04'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-47102'
references:
  - url: 'https://git.kernel.org/stable/c/2efc2256febf214e7b2bdaa21fe6c3c3146acdcb'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5c553a0cd1263e4da5f220d80fa713fc3959c1d0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2efc2256febf214e7b2bdaa21fe6c3c3146acdcb'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/5c553a0cd1263e4da5f220d80fa713fc3959c1d0'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00332
epssPercentile: 0.23687
ingestedAt: '2026-08-05T05:58:02.534Z'
---

## Overview

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]

## Affected

- `linux_kernel >= 5.14, < 5.15.12`
- `linux_kernel = 5.16`

## Remediation

Upgrade past the affected range:

- `linux_kernel 5.15.12`