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| author | Chenyuan Yang <chenyuan0y@gmail.com> | 2025-01-11 19:01:18 +0100 |
|---|---|---|
| committer | Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> | 2025-01-14 17:29:59 +0100 |
| commit | 1b2128aa2d45ab20b22548dcf4b48906298ca7fd (patch) | |
| tree | 4d10cd48a5278ce57a1dbec57a56dbb3dd5514a5 /drivers/platform/x86/dell/dell-uart-backlight.c | |
| parent | platform/x86: intel/pmc: Fix ioremap() of bad address (diff) | |
| download | linux-1b2128aa2d45ab20b22548dcf4b48906298ca7fd.tar.xz linux-1b2128aa2d45ab20b22548dcf4b48906298ca7fd.zip | |
platform/x86: dell-uart-backlight: fix serdev race
The dell_uart_bl_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: 484bae9e4d6a ("platform/x86: Add new Dell UART backlight driver")
Signed-off-by: Chenyuan Yang <chenyuan0y@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20250111180118.2274516-1-chenyuan0y@gmail.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Diffstat (limited to '')
| -rw-r--r-- | drivers/platform/x86/dell/dell-uart-backlight.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/platform/x86/dell/dell-uart-backlight.c b/drivers/platform/x86/dell/dell-uart-backlight.c index 6e5dc7e3674f..bcc5c0f3bb4d 100644 --- a/drivers/platform/x86/dell/dell-uart-backlight.c +++ b/drivers/platform/x86/dell/dell-uart-backlight.c @@ -283,6 +283,9 @@ static int dell_uart_bl_serdev_probe(struct serdev_device *serdev) init_waitqueue_head(&dell_bl->wait_queue); dell_bl->dev = dev; + serdev_device_set_drvdata(serdev, dell_bl); + serdev_device_set_client_ops(serdev, &dell_uart_bl_serdev_ops); + ret = devm_serdev_device_open(dev, serdev); if (ret) return dev_err_probe(dev, ret, "opening UART device\n"); @@ -290,8 +293,6 @@ static int dell_uart_bl_serdev_probe(struct serdev_device *serdev) /* 9600 bps, no flow control, these are the default but set them to be sure */ serdev_device_set_baudrate(serdev, 9600); serdev_device_set_flow_control(serdev, false); - serdev_device_set_drvdata(serdev, dell_bl); - serdev_device_set_client_ops(serdev, &dell_uart_bl_serdev_ops); get_version[0] = DELL_SOF(GET_CMD_LEN); get_version[1] = CMD_GET_VERSION; |