tracing: Fix retry exhaustion in simple ring buffer reader swap (CVE-2026-89748) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89748

tracing: Fix retry exhaustion in simple ring buffer reader swap

Answer in brief

CVE-2026-89748 records a Unknown severity vulnerability in tracing: Fix retry exhaustion in simple ring buffer reader swap. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 11, 2026Updated Sep 11, 2026Source checked Sep 11, 2026First seen by HOL Sep 11, 2026Material review Sep 11, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=34e5b958bdad0f9cf16306368bbc2dc5b2a50143 <df02489aa3aa1834659f0d20c89f7d212047d268 \|\| >=34e5b958bdad0f9cf16306368bbc2dc5b2a50143 <e0d3aed7b12cf37b74c7cc5265073d0263b49cde	df02489aa3aa1834659f0d20c89f7d212047d268, e0d3aed7b12cf37b74c7cc5265073d0263b49cde
Linux/Linuxgeneric	7.1	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to df02489aa3aa1834659f0d20c89f7d212047d268 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 11, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. The current !retry test reverses both outcomes. It returns an error after a successful final replacement, leaving the link update complete but the reader bookkeeping unfinished. After a failed final replacement, it falls through and updates the head and reader pointers as though the replacement succeeded, which can corrupt the ring. Treat only a negative counter as exhaustion and return the documented -EBUSY error.

Quoted source text, attributed separately from HOL analysis.