Executive brief
A vulnerability in the Linux kernel's Equilibrium pin controller driver can cause system instability or warning traces during driver loading. This component manages how hardware pins and interrupts are assigned on certain processors. While primarily resulting in kernel warnings, such flaws can sometimes be leveraged to impact system availability or reliability.
Technical details
The vulnerability exists in the Equilibrium pinctrl driver (drivers/pinctrl/pinctrl-equilibrium.c) due to improper nesting of interrupt callback functions. Specifically, the 'eqbr_irq_mask_ack()' function calls 'eqbr_irq_mask()', which incorrectly invokes 'gpiochip_disable_irq()'. This sequence triggers a kernel warning trace in 'gpiolib.c' for every GPIO on load because the interrupt is being disabled in a context where it is not expected. An attacker with local access could potentially exploit this behavior to cause a denial of service or system instability. The fix involves refactoring 'eqbr_irq_mask_ack()' to perform the necessary register writes directly without calling the problematic 'eqbr_irq_mask()' wrapper.
Affected products
- Linux Linux Kernel 6.4 to 6.6.130, 6.7 to 6.12.77, 6.13 to 6.18.17, 6.19 to 6.19.7
Timeline
- 2026-02-23: patched: Initial patch committed to mainline kernel
- 2026-03-25: disclosed: CVE published
References
- https://git.kernel.org/stable/c/3e00b1b332e54ba50cca6691f628b9c06574024f
- https://git.kernel.org/stable/c/53eba152810ef0fff8567b13ea0f62d48e62df6b
- https://git.kernel.org/stable/c/896449ad9053a42c6c710aeae6175170176cabd0
- https://git.kernel.org/stable/c/af3b0ec98dc1133521b612f8009fdd36b612aabe
- https://git.kernel.org/stable/c/ec54546e8d8a50a9824c139a127a8459d1b0b1bb