CVE-2026-89503

high

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ring_buffer_alloc_read_page() is racy with ring_buffer_subbuf_order_set, it can allocate a reader page with an outdated order.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.

References

https://git.kernel.org/stable/c/e743527c5bfdceda1095bc0a9e596e2aebb6a9c3

https://git.kernel.org/stable/c/53106e9262a310ef2c9a9321168c03705940c678

https://git.kernel.org/stable/c/2dc510957fe8fd098ab3c3147ebdf34d00cd2734

Details

Source: Mitre, NVD

Published: 2026-09-11

Updated: 2026-09-13

Risk Information

CVSS v2

Base Score: 6.8

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

Severity: Medium

CVSS v3

Base Score: 7.8

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00198