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it can allocate a reader page with an outdated order.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.
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it can allocate a reader page with an outdated order.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
See what this means
CVSS v3 Base Score
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 |