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 59616a91e5e74833b2008b56c66879857c616006 ]
The yt2_1380_fc_serdev_probe() function calls 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 devm_serdev_device_open().
Note, serdev_device_set_baudrate() and serdev_device_set_flow_control() calls should be after the devm_serdev_device_open() call.
Fixes: b2ed33e8d486 ("platform/x86: Add lenovo-yoga-tab2-pro-1380-fastcharger driver") Signed-off-by: Chenyuan Yang chenyuan0y@gmail.com Reviewed-by: Hans de Goede hdegoede@redhat.com Link: https://lore.kernel.org/r/20250111180951.2277757-1-chenyuan0y@gmail.com Reviewed-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/x86/lenovo-yoga-tab2-pro-1380-fastcharger.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/platform/x86/lenovo-yoga-tab2-pro-1380-fastcharger.c b/drivers/platform/x86/lenovo-yoga-tab2-pro-1380-fastcharger.c index d525bdc8ca9b3..32d9b6009c422 100644 --- a/drivers/platform/x86/lenovo-yoga-tab2-pro-1380-fastcharger.c +++ b/drivers/platform/x86/lenovo-yoga-tab2-pro-1380-fastcharger.c @@ -199,14 +199,15 @@ static int yt2_1380_fc_serdev_probe(struct serdev_device *serdev) if (ret) return ret;
+ serdev_device_set_drvdata(serdev, fc); + serdev_device_set_client_ops(serdev, &yt2_1380_fc_serdev_ops); + ret = devm_serdev_device_open(dev, serdev); if (ret) return dev_err_probe(dev, ret, "opening UART device\n");
serdev_device_set_baudrate(serdev, 600); serdev_device_set_flow_control(serdev, false); - serdev_device_set_drvdata(serdev, fc); - serdev_device_set_client_ops(serdev, &yt2_1380_fc_serdev_ops);
ret = devm_extcon_register_notifier_all(dev, fc->extcon, &fc->nb); if (ret)