CVE-2026-74320 fbdev: sm501fb: Fix buffer errors in OF binding code
A use-after-free and buffer overrun in the Linux kernel sm501fb driver allows local attackers to execute code or cause a system crash.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74320?
CVE-2026-74320 is an use after free vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
fbdev: sm501fb: Fix buffer errors in OF binding code
The code that gets the frame buffer mode from OF has 'use after free', 'buffer overrun' and memory leaks.
info->edid_data isn't free if the probe functions fail or if pd->def_mode is set.
If both the CRT and PANEL are enabled info->edid_data is used after being freed and is freed twice.
The string returned by of_get_property(np, "mode", &len) is just written over either the static "640x480-16@60" or the module parameter string without any regard for the length (which is most likely longer).
Use kstrump() for the OF mode and free everything before freeing 'info.
Which versions are affected by CVE-2026-74320?
How do I fix CVE-2026-74320?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-74320 being exploited?
There is no known exploitation of CVE-2026-74320 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74320, DEBIAN-CVE-2026-74320, GHSA-cprm-m4x6-j7h5, UBUNTU-CVE-2026-74320.