CVE-2026-74617 dibs: initialise dibs->lock in dibs_dev_alloc()
A race condition in the Linux kernel dibs driver allows a denial of service via an uninitialized lock accessed during interrupt handling.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74617?
CVE-2026-74617 is a critical vulnerability in Linux, published on 22 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
dibs: initialise dibs->lock in dibs_dev_alloc()
dibs->lock is initialised by dibs_dev_add(), but a dibs device can already take interrupts before that call: ism_probe() runs ism_dev_init(), and hence request_irq(), before it calls dibs_dev_add(). No client can have registered a dmb at that point, so no dmb interrupt can occur, but a GID event interrupt can, and ism_handle_irq() takes dibs->lock unconditionally on entry, before it inspects anything else.
Initialise the lock in dibs_dev_alloc() instead, so that it is valid as soon as a driver can publish the device to its interrupt handler.
Which versions are affected by CVE-2026-74617?
How do I fix CVE-2026-74617?
Apply the vendor's patch.
Is CVE-2026-74617 being exploited?
There is no known exploitation of CVE-2026-74617 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74617, DEBIAN-CVE-2026-74617, GHSA-65j5-6jf7-5p7m, UBUNTU-CVE-2026-74617.