fbdev: serialize mode sysfs access with lock_fb_info() (CVE-2026-80785) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-80785

fbdev: serialize mode sysfs access with lock_fb_info()

Answer in brief

CVE-2026-80785 records a Unknown severity vulnerability in fbdev: serialize mode sysfs access with lock_fb_info(). The current sources do not mark it as known exploited. The current feed maps 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 4, 2026Updated Sep 4, 2026Source checked Sep 4, 2026First seen by HOL Sep 4, 2026Material review Sep 4, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
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). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <26135631ed8e487bc6aef70cc41934e258d09bbe \|\| >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <061db6b7a910b8378f3b2df64f8c0a3ddc6e85f2 \|\| >=0 <7.1.11	26135631ed8e487bc6aef70cc41934e258d09bbe, 061db6b7a910b8378f3b2df64f8c0a3ddc6e85f2, 7.1.11

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux.
Review the reported fix. Update Linux/Linux to 26135631ed8e487bc6aef70cc41934e258d09bbe if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 4, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: fbdev: serialize mode sysfs access with lock_fb_info() show_mode(), show_modes(), and store_mode() access fb_info->modelist and fb_info->mode without holding lock_fb_info(). store_modes() takes lock_fb_info() while replacing the modelist and freeing the old one. A concurrent reader or writer can load a pointer to an old modelist entry before store_modes() frees it, then dereference freed memory or store a stale freed pointer in fb_info->mode. Take lock_fb_info() in show_mode(), show_modes(), and store_mode() to serialize with store_modes(). In show_mode(), copy the mode to the stack and format after dropping the lock. In store_mode(), split activate() into a _locked variant to avoid double-locking, and hold the locks for the modelist walk, mode conversion, activation, and fb_info->mode assignment together.

Quoted source text, attributed separately from HOL analysis.