CVE-2026-80999

Received Received - Intake

Use of gpiod_set_value_cansleep in Linux Kernel DSA Realtek Driver

Publication date: 2026-09-11

Last updated on: 2026-09-11

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO rtl83xx_reset_assert() and rtl83xx_reset_deassert() are only called from the probe path, which may sleep and is not timing-critical. When the reset GPIO is provided by a sleeping controller such as an I2C I/O expander, gpiod_set_value() warns: WARNING: drivers/gpio/gpiolib.c:4030 at gpiod_set_value+0x44/0x80, CPU#1: kworker/u16:4/61 Hardware name: B&O MAP CA33 Rev f (UNKNOWN) (DT) Workqueue: events_unbound deferred_probe_work_func pc : gpiod_set_value+0x44/0x80 lr : rtl83xx_probe+0x1d8/0x3a0 Call trace: gpiod_set_value+0x44/0x80 (P) rtl83xx_probe+0x1d8/0x3a0 realtek_mdio_probe+0x24/0xa0 mdio_probe+0x38/0x78 really_probe+0xc4/0x3e0 __driver_probe_device+0x15c/0x1b8 driver_probe_device+0xb4/0x120 __device_attach_driver+0xb8/0x1a0 bus_for_each_drv+0x88/0xf0 __device_attach+0xa0/0x1d8 device_initial_probe+0x54/0x68 bus_probe_device+0x38/0xa0 deferred_probe_work_func+0xb8/0x120 process_one_work+0x184/0x4e8 worker_thread+0x188/0x308 kthread+0x130/0x150 ret_from_fork+0x10/0x20 Switch both helpers to gpiod_set_value_cansleep() so such a reset GPIO can be used without triggering the warning. The reset GPIO has been driven with the non-sleeping gpiod_set_value() since the driver was added in v4.19. The call has since been refactored across several files - from realtek-smi.c / realtek-mdio.c into the common rtl83xx.c module and then into the rtl83xx_reset_assert() and rtl83xx_reset_deassert() helpers (both in v6.9). This patch therefore applies as-is only to kernels that carry those helpers (v6.9+); older stable kernels need the same gpiod_set_value_cansleep() conversion at the corresponding open-coded call sites.

CVSS Scores

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Meta Information

Published

2026-09-11

Last Modified

2026-09-11

Generated

2026-10-02

AI Q&A

2026-09-12

EPSS Evaluated

2026-10-01

NVD

CVE-2026-80999

EUVD

EUVD-2026-76322

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	From 6.9 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This is not a vulnerability but a bug fix in the Linux kernel. The issue involves the use of gpiod_set_value() for reset GPIO operations in the Realtek DSA driver. The function gpiod_set_value() cannot sleep, but the reset GPIO may be provided by a sleeping controller like an I2C I/O expander. This causes a warning when the driver probes. The fix replaces gpiod_set_value() with gpiod_set_value_cansleep() to allow sleeping controllers.

Detection Guidance

This vulnerability is specific to the Linux kernel's Realtek DSA driver and may trigger a warning when using reset GPIOs with sleeping controllers. Detection involves checking kernel logs for the warning message about gpiod_set_value() during driver probe. Use dmesg | grep gpiod_set_value to search for related warnings.

Impact Analysis

This is not a vulnerability, so it does not pose a security risk. However, if you use a Realtek switch with an I2C I/O expander for reset GPIO, the kernel may log warnings during device probing. This could cause delays or failures in device initialization but does not affect functionality or security.

Compliance Impact

This is not a vulnerability and does not impact compliance with standards like GDPR or HIPAA. The issue is a kernel warning during device probing and does not involve data exposure, privacy risks, or regulatory violations.

Mitigation Strategies

Apply the kernel patch that replaces gpiod_set_value() with gpiod_set_value_cansleep() in the Realtek DSA driver. Update to a kernel version containing this fix (v6.9+). For older kernels, manually patch the driver code at the relevant call sites.

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