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serial: 8250_dw: unregister 8250 port if clk_notifier_register() fails

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dw8250_probe() registers the 8250 port via serial8250_register_8250_port()
and then, if the device has a clock, registers a clock notifier. If
clk_notifier_register() fails, probe returns the error but leaves the
8250 port registered. The matching serial8250_unregister_port() lives
in dw8250_remove(), which is not called when probe fails, so the port
slot stays occupied until the device is rebound or the system is
rebooted. The devm-allocated driver data is freed while the port still
references it (via the saved private_data and serial_in/serial_out
callbacks), so any access to that port slot before a rebind is a
use-after-free hazard.

Unregister the port on the clk_notifier_register() error path.

Fixes: cc816969d7 ("serial: 8250_dw: Fix common clocks usage race condition")
Cc: stable@vger.kernel.org
Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260514143746.23671-2-sozdayvek@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Stepan Ionichev
2026-05-14 19:37:45 +05:00
committed by Greg Kroah-Hartman
parent d9ee199c0f
commit 10fc708b4d
1 changed files with 3 additions and 1 deletions
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4
drivers/tty/serial/8250/8250_dw.c
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@@ -839,8 +839,10 @@ static int dw8250_probe(struct platform_device *pdev)
*/
if (data->clk) {
err = clk_notifier_register(data->clk, &data->clk_notifier);
if (err)
if (err) {
serial8250_unregister_port(data->data.line);
return dev_err_probe(dev, err, "Failed to set the clock notifier\n");
}
queue_work(system_dfl_wq, &data->clk_work);
}