linux/linux-stable.git - Linux kernel stable tree

Age	Commit message (Collapse)	Author
2025-02-03	w1: fix NULL pointer dereference in probe	Chenyuan Yang
	The w1_uart_probe() function calls w1_uart_serdev_open() (which includes devm_serdev_device_open()) before setting the client ops via serdev_device_set_client_ops(). This ordering can trigger a NULL pointer dereference in the serdev controller's receive_buf handler, as it assumes serdev->ops is valid when SERPORT_ACTIVE is set. This is similar to the issue fixed in commit 5e700b384ec1 ("platform/chrome: cros_ec_uart: properly fix race condition") where devm_serdev_device_open() was called before fully initializing the device. Fix the race by ensuring client ops are set before enabling the port via w1_uart_serdev_open(). Fixes: a3c08804364e ("w1: add UART w1 bus driver") Signed-off-by: Chenyuan Yang <chenyuan0y@gmail.com> Acked-by: Christoph Winklhofer <cj.winklhofer@gmail.com> Link: https://lore.kernel.org/r/20250111181803.2283611-1-chenyuan0y@gmail.com Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
2024-02-15	w1: add UART w1 bus driver	Christoph Winklhofer
	Add a UART 1-Wire bus driver. The driver utilizes the UART interface via the Serial Device Bus to create the 1-Wire timing patterns. The driver was tested on a "Raspberry Pi 3B" with a DS18B20 and on a "Variscite DART-6UL" with a DS18S20 temperature sensor. The 1-Wire timing pattern and the corresponding UART baud-rate with the interpretation of the transferred bytes are described in the document: Link: https://www.analog.com/en/technical-articles/using-a-uart-to-implement-a-1wire-bus-master.html In short, the UART peripheral must support full-duplex and operate in open-drain mode. The timing patterns are generated by a specific combination of baud-rate and transmitted byte, which corresponds to a 1-Wire read bit, write bit or reset. Signed-off-by: Christoph Winklhofer <cj.winklhofer@gmail.com> Link: https://lore.kernel.org/r/20240214-w1-uart-v7-3-6e21fa24e066@gmail.com [krzysztof: w1_uart_serdev_receive_buf() return type fixup] Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>