6.6-stable review patch. If anyone has any objections, please let me know.
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From: Jiri Slaby (SUSE) jirislaby@kernel.org
[ Upstream commit d0009a32c9e4e083358092f3c97e3c6e803a8930 ]
Coverity reports (as CID 1536978) that uart_poll_init() passes uninitialized pm_state to uart_change_pm(). It is in case the first 'if' takes the true branch (does "goto out;").
Fix this and simplify the function by simple guard(mutex). The code needs no labels after this at all. And it is pretty clear that the code has not fiddled with pm_state at that point.
Signed-off-by: Jiri Slaby (SUSE) jirislaby@kernel.org Fixes: 5e227ef2aa38 (serial: uart_poll_init() should power on the UART) Cc: stable@vger.kernel.org Cc: Douglas Anderson dianders@chromium.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Reviewed-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Reviewed-by: Douglas Anderson dianders@chromium.org Link: https://lore.kernel.org/r/20240805102046.307511-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/serial/serial_core.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 3fb55f46a8914..5d5570bebfeb6 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -2694,14 +2694,13 @@ static int uart_poll_init(struct tty_driver *driver, int line, char *options) int ret = 0;
tport = &state->port; - mutex_lock(&tport->mutex); + + guard(mutex)(&tport->mutex);
port = uart_port_check(state); if (!port || port->type == PORT_UNKNOWN || - !(port->ops->poll_get_char && port->ops->poll_put_char)) { - ret = -1; - goto out; - } + !(port->ops->poll_get_char && port->ops->poll_put_char)) + return -1;
pm_state = state->pm_state; uart_change_pm(state, UART_PM_STATE_ON); @@ -2721,10 +2720,10 @@ static int uart_poll_init(struct tty_driver *driver, int line, char *options) ret = uart_set_options(port, NULL, baud, parity, bits, flow); console_list_unlock(); } -out: + if (ret) uart_change_pm(state, pm_state); - mutex_unlock(&tport->mutex); + return ret; }