This is a note to let you know that I've just added the patch titled
serial: core: mark port as initialized after successful IRQ change
to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
serial-core-mark-port-as-initialized-after-successful-irq-change.patch
and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 44117a1d1732c513875d5a163f10d9adbe866c08 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Date: Thu, 11 Jan 2018 18:57:26 +0100
Subject: serial: core: mark port as initialized after successful IRQ change
From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
commit 44117a1d1732c513875d5a163f10d9adbe866c08 upstream.
setserial changes the IRQ via uart_set_info(). It invokes
uart_shutdown() which free the current used IRQ and clear
TTY_PORT_INITIALIZED. It will then update the IRQ number and invoke
uart_startup() before returning to the caller leaving
TTY_PORT_INITIALIZED cleared.
The next open will crash with
| list_add double add: new=ffffffff839fcc98, prev=ffffffff839fcc98, next=ffffffff839fcc98.
since the close from the IOCTL won't free the IRQ (and clean the list)
due to the TTY_PORT_INITIALIZED check in uart_shutdown().
There is same pattern in uart_do_autoconfig() and I *think* it also
needs to set TTY_PORT_INITIALIZED there.
Is there a reason why uart_startup() does not set the flag by itself
after the IRQ has been acquired (since it is cleared in uart_shutdown)?
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/serial_core.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -974,6 +974,8 @@ static int uart_set_info(struct tty_stru
}
} else {
retval = uart_startup(tty, state, 1);
+ if (retval == 0)
+ tty_port_set_initialized(port, true);
if (retval > 0)
retval = 0;
}
Patches currently in stable-queue which might be from bigeasy@xxxxxxxxxxxxx are
queue-4.15/serial-core-mark-port-as-initialized-after-successful-irq-change.patch