0.0
NA
CVE-2021-47223
Linux Kernel Bridge VLAN Tunnel Null Pointer Dereference
Description

In the Linux kernel, the following vulnerability has been resolved: net: bridge: fix vlan tunnel dst null pointer dereference This patch fixes a tunnel_dst null pointer dereference due to lockless access in the tunnel egress path. When deleting a vlan tunnel the tunnel_dst pointer is set to NULL without waiting a grace period (i.e. while it's still usable) and packets egressing are dereferencing it without checking. Use READ/WRITE_ONCE to annotate the lockless use of tunnel_id, use RCU for accessing tunnel_dst and make sure it is read only once and checked in the egress path. The dst is already properly RCU protected so we don't need to do anything fancy than to make sure tunnel_id and tunnel_dst are read only once and checked in the egress path.

INFO

Published Date :

May 21, 2024, 3:15 p.m.

Last Modified :

May 21, 2024, 4:54 p.m.

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Remotely Exploitable :

No

Impact Score :

Exploitability Score :

Affected Products

The following products are affected by CVE-2021-47223 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-47223.

URL Resource
https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530
https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f
https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c
https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d
https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79
https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-47223 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-47223 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    May. 28, 2024

    Action Type Old Value New Value
  • CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    May. 21, 2024

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: net: bridge: fix vlan tunnel dst null pointer dereference This patch fixes a tunnel_dst null pointer dereference due to lockless access in the tunnel egress path. When deleting a vlan tunnel the tunnel_dst pointer is set to NULL without waiting a grace period (i.e. while it's still usable) and packets egressing are dereferencing it without checking. Use READ/WRITE_ONCE to annotate the lockless use of tunnel_id, use RCU for accessing tunnel_dst and make sure it is read only once and checked in the egress path. The dst is already properly RCU protected so we don't need to do anything fancy than to make sure tunnel_id and tunnel_dst are read only once and checked in the egress path.
    Added Reference kernel.org https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f [No types assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-47223 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-47223 weaknesses.

NONE - Vulnerability Scoring System
: