35 lines
1.4 KiB
Diff
35 lines
1.4 KiB
Diff
From: David Howells <dhowells@redhat.com>
|
|
Date: Wed, 8 Nov 2017 15:11:35 +0000
|
|
Subject: [21/29] Lock down TIOCSSERIAL
|
|
Origin: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/commit?id=f5fdeda0622ca040961521819794193777a03e8a
|
|
|
|
Lock down TIOCSSERIAL as that can be used to change the ioport and irq
|
|
settings on a serial port. This only appears to be an issue for the serial
|
|
drivers that use the core serial code. All other drivers seem to either
|
|
ignore attempts to change port/irq or give an error.
|
|
|
|
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
cc: Jiri Slaby <jslaby@suse.com>
|
|
---
|
|
drivers/tty/serial/serial_core.c | 6 ++++++
|
|
1 file changed, 6 insertions(+)
|
|
|
|
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
|
|
index 3a14cccbd7ff..41f0922ad842 100644
|
|
--- a/drivers/tty/serial/serial_core.c
|
|
+++ b/drivers/tty/serial/serial_core.c
|
|
@@ -842,6 +842,12 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
|
|
new_flags = (__force upf_t)new_info->flags;
|
|
old_custom_divisor = uport->custom_divisor;
|
|
|
|
+ if ((change_port || change_irq) &&
|
|
+ kernel_is_locked_down("Using TIOCSSERIAL to change device addresses, irqs and dma channels")) {
|
|
+ retval = -EPERM;
|
|
+ goto exit;
|
|
+ }
|
|
+
|
|
if (!capable(CAP_SYS_ADMIN)) {
|
|
retval = -EPERM;
|
|
if (change_irq || change_port ||
|