The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x d0009a32c9e4e083358092f3c97e3c6e803a8930 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024100108-attention-muppet-0778@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
d0009a32c9e4 ("serial: don't use uninitialized value in uart_poll_init()") 788aeef392d2 ("tty: serial: kgdboc: Fix 8250_* kgdb over serial")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d0009a32c9e4e083358092f3c97e3c6e803a8930 Mon Sep 17 00:00:00 2001 From: "Jiri Slaby (SUSE)" jirislaby@kernel.org Date: Mon, 5 Aug 2024 12:20:36 +0200 Subject: [PATCH] serial: don't use uninitialized value in uart_poll_init() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
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
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 83c5bccc5086..e0aac155dca2 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -2690,14 +2690,13 @@ 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); @@ -2717,10 +2716,10 @@ 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; }