In the Linux kernel, the following vulnerability has been resolved: auxdisplay: charlcd: cancel backlight work on registration failure With… (CVE-2026-89585)
A vulnerability in the Linux kernel's auxdisplay charlcd driver was resolved by ensuring that backlight work is canceled if registration fails. The issue involved delayed work referencing freed memory if the charlcd device registration failed, potentially leading to use-after-free conditions.
AI Analysis
Technical Summary
The Linux kernel vulnerability (CVE-2026-89585) concerns the auxdisplay charlcd driver where, with CONFIG_CHARLCD_BL_FLASH enabled, the charlcd_init() function schedules delayed backlight work before the device is fully registered via misc_register(). If the registration fails, the charlcd object is freed while the delayed work still references its address, causing a use-after-free scenario. The fix adds a charlcd_deinit() function to cancel the delayed work and turn off the backlight, used both for rollback on registration failure and normal unregistration.
Potential Impact
The vulnerability could lead to use-after-free conditions in kernel space, which may cause system instability or crashes. The input data does not specify exploitation details or broader impact such as privilege escalation or information disclosure.
Mitigation Recommendations
A fix has been implemented by adding charlcd_deinit() to properly cancel delayed work on registration failure and unregistration. Users should apply the official Linux kernel update that includes this fix. No additional mitigation steps are indicated.
In the Linux kernel, the following vulnerability has been resolved: auxdisplay: charlcd: cancel backlight work on registration failure With… (CVE-2026-89585)
Description
A vulnerability in the Linux kernel's auxdisplay charlcd driver was resolved by ensuring that backlight work is canceled if registration fails. The issue involved delayed work referencing freed memory if the charlcd device registration failed, potentially leading to use-after-free conditions.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel vulnerability (CVE-2026-89585) concerns the auxdisplay charlcd driver where, with CONFIG_CHARLCD_BL_FLASH enabled, the charlcd_init() function schedules delayed backlight work before the device is fully registered via misc_register(). If the registration fails, the charlcd object is freed while the delayed work still references its address, causing a use-after-free scenario. The fix adds a charlcd_deinit() function to cancel the delayed work and turn off the backlight, used both for rollback on registration failure and normal unregistration.
Potential Impact
The vulnerability could lead to use-after-free conditions in kernel space, which may cause system instability or crashes. The input data does not specify exploitation details or broader impact such as privilege escalation or information disclosure.
Mitigation Recommendations
A fix has been implemented by adding charlcd_deinit() to properly cancel delayed work on registration failure and unregistration. Users should apply the official Linux kernel update that includes this fix. No additional mitigation steps are indicated.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-72rp-5pw2-wrgc
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-89585"]
Threat ID: 6aa4a00d55bf5e2cf5a86688
Added to database: 09/12/2026, 00:42:53 UTC
Last enriched: 09/12/2026, 01:04:01 UTC
Last updated: 09/12/2026, 01:04:01 UTC
Views: 2
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