CVE-2026-89771
What it is
In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix subbuf resize race with ring buffer readers trace_buffer subbuf_size is read lockless in ring_buffer_read_page() and ring_buffer_read_start(), while it can simultaneously be resized with ring_buffer_subbuf_order_set(). Instead of trace_buffer::subbuf_size, use bpage::order in ring_buffer_read_start() and ring_buffer_read_page(). In ring_buffer_read_start(), even with resize_disabled, there is still a possibility of a race with a buffer modification. Hold the trace_buffer mutex to synchronise with any pending ring buffer order modification. trace_buffer::subbuf_size is now actually useless, remove it. Also, create accessors rb_subbuf_capacity() and rb_page_capacity() which return the actual size available for storing events, while rb_subbuf_size() returns the actual subbuf page-size.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Record status
- Received
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-89771.md and follow it. Check whether this project is affected by CVE-2026-89771. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
