6.12-stable review patch. If anyone has any objections, please let me know.
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From: Chenyuan Yang chenyuan0y@gmail.com
[ Upstream commit 0dd6770a72f138dabea9eae87f3da6ffa68f0d06 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/w1/masters/w1-uart.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/w1/masters/w1-uart.c b/drivers/w1/masters/w1-uart.c index a31782e56ba75..c87eea3478067 100644 --- a/drivers/w1/masters/w1-uart.c +++ b/drivers/w1/masters/w1-uart.c @@ -372,11 +372,11 @@ static int w1_uart_probe(struct serdev_device *serdev) init_completion(&w1dev->rx_byte_received); mutex_init(&w1dev->rx_mutex);
+ serdev_device_set_drvdata(serdev, w1dev); + serdev_device_set_client_ops(serdev, &w1_uart_serdev_ops); ret = w1_uart_serdev_open(w1dev); if (ret < 0) return ret; - serdev_device_set_drvdata(serdev, w1dev); - serdev_device_set_client_ops(serdev, &w1_uart_serdev_ops);
return w1_add_master_device(&w1dev->bus); }