CVE-2026-89503

Public on 2026-09-11
Modified on 2026-09-15
Description
In the Linux kernel, the following vulnerability has been resolved:

ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page()

ring_buffer_alloc_read_page() is racy with ring_buffer_subbuf_order_set,
it can allocate a reader page with an outdated order. This isn't a big
issue, the user can still re-allocate a new reader page and try again.

However, what is more problematic is if the value of subbuf_order
changes in the middle of ring_buffer_alloc_read_page(). In that case,
bpage->order might not match the actual allocated memory.

Use bpage->order for the allocation to prevent this race.
Severity
Medium severity
Medium
See what this means
CVSS v3 Base Score
4.1
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Core kernel Not Affected
Amazon Linux 2 - Kernel-5.10 Extra kernel Not Affected
Amazon Linux 2 - Kernel-5.15 Extra kernel Not Affected
Amazon Linux 2 - Kernel-5.4 Extra kernel Not Affected
Amazon Linux 2023 kernel Not Affected
Amazon Linux 2023 kernel6.12 Pending Fix
Amazon Linux 2023 kernel6.18 Pending Fix
Amazon Linux 2027 Preview kernel7.1 Pending Fix

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 4.1 CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H