Rapid7 Vulnerability & Exploit Database

Debian: CVE-2021-47223: linux -- security update

Free InsightVM Trial No Credit Card Necessary
2024 Attack Intel Report Latest research by Rapid7 Labs
Back to Search

Debian: CVE-2021-47223: linux -- security update

Severity
4
CVSS
(AV:L/AC:M/Au:N/C:P/I:P/A:P)
Published
05/21/2024
Created
07/31/2024
Added
07/30/2024
Modified
07/30/2024

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.

Solution(s)

  • debian-upgrade-linux

With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.

– Scott Cheney, Manager of Information Security, Sierra View Medical Center

;