NULL Pointer Dereference Affecting perf-debuginfo package, versions <0:4.14.238-182.421.amzn2


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.05% (15th percentile)

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  • Snyk IDSNYK-AMZN2-PERFDEBUGINFO-10264195
  • published30 May 2025
  • disclosed21 May 2024

Introduced: 21 May 2024

CVE-2021-47223  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2 perf-debuginfo to version 0:4.14.238-182.421.amzn2 or higher.
This issue was patched in ALAS2-2021-1685.

NVD Description

Note: Versions mentioned in the description apply only to the upstream perf-debuginfo package and not the perf-debuginfo package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1