CVE-2026-90433 spi: oc-tiny: switch to managed controller allocation
A use-after-free vulnerability in the Linux kernel's oc-tiny SPI driver allows attackers to cause a denial of service or potentially execute code via late interrupts.
- 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-2026-90433?
CVE-2026-90433 is an use after free 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:
spi: oc-tiny: switch to managed controller allocation
The controller is allocated with the non-managed spi_alloc_host() while the interrupt is registered with devm_request_irq(). During removal, spi_bitbang_stop() only unregisters the controller; the subsequent spi_controller_put() then frees the controller together with its embedded driver-private devdata, which is the IRQ handler's dev_id. The devm_request_irq() release action (free_irq()), which drains the handler, does not run until after .remove() returns. A late or latched interrupt can therefore reach tiny_spi_irq() and dereference already-freed memory (e.g. hw->base).
Switch to devm_spi_alloc_host() so that the devres LIFO order releases the controller only after free_irq() has drained the handler, and drop the now-redundant spi_controller_put() from .remove(). The probe error path is simplified to direct returns.
This issue was found by an in-house static analysis tool.
Which versions are affected by CVE-2026-90433?
How do I fix CVE-2026-90433?
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-2026-90433 being exploited?
There is no known exploitation of CVE-2026-90433 in the wild and no public exploit code.
Sources
Also known as AZL-102828, BELL-CVE-2026-90433, DEBIAN-CVE-2026-90433, GHSA-mj54-2c5f-648c, UBUNTU-CVE-2026-90433.