CVE-2026-31689 EDAC/mc: Fix error path ordering in edac_mc_alloc()
A null pointer dereference in the Linux kernel EDAC subsystem causes a system crash when memory allocation fails during initialization.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-31689?
CVE-2026-31689 is a medium-severity vulnerability in Linux kernel, published on 27 Apr 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:
EDAC/mc: Fix error path ordering in edac_mc_alloc()
When the mci->pvt_info allocation in edac_mc_alloc() fails, the error path will call put_device() which will end up calling the device's release function.
However, the init ordering is wrong such that device_initialize() happens *after* the failed allocation and thus the device itself and the release function pointer are not initialized yet when they're called:
MCE: In-kernel MCE decoding enabled. ------------[ cut here ]------------ kobject: '(null)': is not initialized, yet kobject_put() is being called. WARNING: lib/kobject.c:734 at kobject_put, CPU#22: systemd-udevd CPU: 22 UID: 0 PID: 538 Comm: systemd-udevd Not tainted 7.0.0-rc1+ #2 PREEMPT(full) RIP: 0010:kobject_put Call Trace: <TASK> edac_mc_alloc+0xbe/0xe0 [edac_core] amd64_edac_init+0x7a4/0xff0 [amd64_edac] ? __pfx_amd64_edac_init+0x10/0x10 [amd64_edac] do_one_initcall ...
Reorder the calling sequence so that the device is initialized and thus the release function pointer is properly set before it can be used.
This was found by Claude while reviewing another EDAC patch.
Weakness: CWE-476
Which versions are affected by CVE-2026-31689?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31689?
Apply the vendor's patch.
Is CVE-2026-31689 being exploited?
There is no known exploitation of CVE-2026-31689 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-84404, BELL-CVE-2026-31689, DEBIAN-CVE-2026-31689, GHSA-9qrw-cmg5-g8vq, ROOT-OS-DEBIAN-12-CVE-2026-31689, ROOT-OS-UBUNTU-2404-CVE-2026-31689 and 1 more.