Use of Function with Inconsistent Implementations Affecting perf6.18-debuginfo package, versions <1:6.18.20-20.229.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.01% (4th percentile)

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  • Snyk IDSNYK-AMZN2023-PERF618DEBUGINFO-16349964
  • published3 May 2026
  • disclosed3 Apr 2026

Introduced: 3 Apr 2026

CVE-2026-23472  (opens in a new tab)
CWE-474  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 perf6.18-debuginfo to version 1:6.18.20-20.229.amzn2023 or higher.
This issue was patched in ALAS2023-2026-1596.

NVD Description

Note: Versions mentioned in the description apply only to the upstream perf6.18-debuginfo package and not the perf6.18-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:

serial: core: fix infinite loop in handle_tx() for PORT_UNKNOWN

uart_write_room() and uart_write() behave inconsistently when xmit_buf is NULL (which happens for PORT_UNKNOWN ports that were never properly initialized):

  • uart_write_room() returns kfifo_avail() which can be > 0
  • uart_write() checks xmit_buf and returns 0 if NULL

This inconsistency causes an infinite loop in drivers that rely on tty_write_room() to determine if they can write:

while (tty_write_room(tty) > 0) { written = tty->ops->write(...); // written is always 0, loop never exits }

For example, caif_serial's handle_tx() enters an infinite loop when used with PORT_UNKNOWN serial ports, causing system hangs.

Fix by making uart_write_room() also check xmit_buf and return 0 if it's NULL, consistent with uart_write().

Reproducer: https://gist.github.com/mrpre/d9a694cc0e19828ee3bc3b37983fde13

CVSS Base Scores

version 3.1