NULL Pointer Dereference Affecting kernel-debuginfo package, versions <1:6.1.168-202.320.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.01% (4th percentile)

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  • Snyk IDSNYK-AMZN2023-KERNELDEBUGINFO-16625878
  • published10 May 2026
  • disclosed13 Apr 2026

Introduced: 13 Apr 2026

CVE-2026-31422  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel-debuginfo to version 1:6.1.168-202.320.amzn2023 or higher.
This issue was patched in ALAS2023-2026-1681.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-debuginfo package and not the kernel-debuginfo package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

net/sched: cls_flow: fix NULL pointer dereference on shared blocks

flow_change() calls tcf_block_q() and dereferences q->handle to derive a default baseclass. Shared blocks leave block->q NULL, causing a NULL deref when a flow filter without a fully qualified baseclass is created on a shared block.

Check tcf_block_shared() before accessing block->q and return -EINVAL for shared blocks. This avoids the null-deref shown below:

======================================================================= KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:flow_change (net/sched/cls_flow.c:508) Call Trace: tc_new_tfilter (net/sched/cls_api.c:2432) rtnetlink_rcv_msg (net/core/rtnetlink.c:6980) [...]

CVSS Base Scores

version 3.1