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.
net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO