CVE-2026-64521 pinctrl: meson: amlogic-a4: fix deadlock issue
A local attacker can cause a system deadlock by accessing a specific sysfs node in the Linux kernel pinctrl driver, leading to denial of service.
- 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-2026-64521?
CVE-2026-64521 is a denial of service vulnerability in Linux, published on 25 Jul 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:
pinctrl: meson: amlogic-a4: fix deadlock issue
Accessing the pinconf-pins sysfs node may deadlock.
pinconf_pins_show() holds pctldev->mutex, and the platform driver calls pinctrl_find_gpio_range_from_pin(), which tries to acquire the same mutex again, leading to a deadlock.
Use pinctrl_find_gpio_range_from_pin_nolock() to fix this issue.
Which versions are affected by CVE-2026-64521?
How do I fix CVE-2026-64521?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-64521 being exploited?
There is no known exploitation of CVE-2026-64521 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-64521, DEBIAN-CVE-2026-64521, GHSA-gf4r-jj9w-gcc4, ROOT-OS-UBUNTU-2204-CVE-2026-64521, UBUNTU-CVE-2026-64521.