Linux Kernel up to 7.1.9 fbdev fb_set_var use after free

Summaryinfo

A vulnerability identified as very critical has been detected in Linux Kernel up to 7.1.9. Affected by this vulnerability is the function fb_set_var of the component fbdev. Performing a manipulation results in use after free. This vulnerability is identified as CVE-2026-80579. The attack is only possible with local access. There is not any exploit available.

Detailsinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 7.1.9. This affects the function fb_set_var of the component fbdev. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: fbdev: clear fb_info->mode before deleting a videomode fb_set_var() can delete a mode from info->modelist when userspace passes FB_ACTIVATE_INV_MODE through FBIOPUT_VSCREENINFO. The code checks that the mode being deleted is not the current info->var and that fbcon is not using it, but it does not check fb_info->mode. fb_info->mode may still point into the modelist entry being deleted. If the entry is freed, later mode sysfs reads through show_mode() can dereference a stale pointer. Clear fb_info->mode before calling fb_delete_videomode() when it matches the mode being removed.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-80579 since 08/26/2026. The exploitability is told to be easy. An attack has to be approached locally. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/26/2026).

Upgrading to version 7.1.10 eliminates this vulnerability. Applying the patch ce7fef961c63229b22dec415fb988899f479d61f/95e647d2a5304a8fd11f1ba3c8502de700650131 is able to eliminate this problem.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.4
• 7.1.5
• 7.1.6
• 7.1.7
• 7.1.8
• 7.1.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

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