CVE-2026-93086 firmware: arm_scmi: Avoid IDR updates while cleaning channels
A race condition in the Linux kernel SCMI driver can cause a denial of service during channel cleanup.
- 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-2026-93086?
CVE-2026-93086 is a vulnerability in Linux, published on 17 Sep 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:
firmware: arm_scmi: Avoid IDR updates while cleaning channels
scmi_cleanup_channels() walks the TX/RX channel IDRs with idr_for_each() to free transport resources and destroy the dedicated transport devices before calling idr_destroy().
The destroy callback removed each entry from the same IDR being walked. That is not needed for this cleanup path, and it is unsafe because idr_for_each() has not advanced its radix-tree iterator while the callback is running. Removing the current entry from the callback can invalidate the iterator state. The callback also cannot be protected by rcu_read_lock(), because scmi_device_destroy() may sleep.
Leave IDR teardown to the following idr_destroy() call and keep the callback limited to device destruction.
Which versions are affected by CVE-2026-93086?
How do I fix CVE-2026-93086?
Apply the vendor's patch.
Is CVE-2026-93086 being exploited?
There is no known exploitation of CVE-2026-93086 in the wild and no public exploit code.
Sources
Also known as AZL-102410, BELL-CVE-2026-93086, DEBIAN-CVE-2026-93086, GHSA-w3xq-cq2m-6h87, UBUNTU-CVE-2026-93086.