From: Matthew Garrett <matthewgarrett@google.com>
To: jmorris@namei.org
Cc: linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, dhowells@redhat.com,
linux-api@vger.kernel.org, luto@kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Matthew Garrett <mjg59@google.com>, Jiri Slaby <jslaby@suse.com>,
linux-serial@vger.kernel.org
Subject: [PATCH V32 17/27] Lock down TIOCSSERIAL
Date: Wed, 3 Apr 2019 17:32:39 -0700 [thread overview]
Message-ID: <20190404003249.14356-18-matthewgarrett@google.com> (raw)
In-Reply-To: <20190404003249.14356-1-matthewgarrett@google.com>
From: David Howells <dhowells@redhat.com>
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>
Signed-off-by: Matthew Garrett <mjg59@google.com>
cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
---
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 d4cca5bdaf1c..65b67f0d4386 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", LOCKDOWN_INTEGRITY)) {
+ retval = -EPERM;
+ goto exit;
+ }
+
if (!capable(CAP_SYS_ADMIN)) {
retval = -EPERM;
if (change_irq || change_port ||
--
2.21.0.392.gf8f6787159e-goog
next prev parent reply other threads:[~2019-04-04 0:32 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-04 0:32 [PATCH V32 0/27] Lockdown patches for 5.2 Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 01/27] Add the ability to lock down access to the running kernel image Matthew Garrett
2019-04-16 8:40 ` Andrew Donnellan
2019-04-18 6:38 ` Daniel Axtens
2019-04-18 19:35 ` Matthew Garrett
2019-04-29 0:06 ` Daniel Axtens
2019-04-29 4:54 ` Daniel Axtens
2019-04-30 5:15 ` Andrew Donnellan
2019-04-29 22:56 ` Matthew Garrett
2019-05-02 21:07 ` James Morris
2019-05-02 21:15 ` Matthew Garrett
2019-05-02 23:19 ` James Morris
2019-05-03 0:34 ` Andy Lutomirski
2019-04-04 0:32 ` [PATCH V32 02/27] Enforce module signatures if the kernel is locked down Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 03/27] Restrict /dev/{mem,kmem,port} when " Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 04/27] kexec_load: Disable at runtime if " Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 06/27] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Matthew Garrett
[not found] ` <20190404003249.14356-1-matthewgarrett-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2019-04-04 0:32 ` [PATCH V32 05/27] Copy secure_boot flag in boot params across kexec reboot Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 07/27] kexec_file: Restrict at runtime if the kernel is locked down Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 08/27] hibernate: Disable when " Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 09/27] uswsusp: " Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 10/27] PCI: Lock down BAR access " Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 11/27] x86: Lock down IO port " Matthew Garrett
2019-04-04 7:49 ` Thomas Gleixner
2019-04-04 0:32 ` [PATCH V32 12/27] x86/msr: Restrict MSR " Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 13/27] ACPI: Limit access to custom_method " Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 14/27] acpi: Ignore acpi_rsdp kernel param when the kernel has been " Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 15/27] acpi: Disable ACPI table override if the kernel is " Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 16/27] Prohibit PCMCIA CIS storage when " Matthew Garrett
2019-04-04 0:32 ` Matthew Garrett [this message]
2019-04-04 0:32 ` [PATCH V32 18/27] Lock down module params that specify hardware parameters (eg. ioport) Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 19/27] x86/mmiotrace: Lock down the testmmiotrace module Matthew Garrett
2019-04-04 1:33 ` Steven Rostedt
2019-04-04 7:47 ` Thomas Gleixner
2019-04-04 0:32 ` [PATCH V32 20/27] Lock down /proc/kcore Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 21/27] Lock down tracing and perf kprobes when in confidentiality mode Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 22/27] bpf: Restrict bpf when kernel lockdown is " Matthew Garrett
2019-04-30 19:19 ` Jann Horn
2019-04-04 0:32 ` [PATCH V32 23/27] Lock down perf when " Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 24/27] kexec: Allow kexec_file() with appropriate IMA policy when locked down Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 25/27] lockdown: Print current->comm in restriction messages Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 26/27] debugfs: Restrict debugfs when the kernel is locked down Matthew Garrett
2019-04-04 0:32 ` [PATCH V32 27/27] tracefs: Restrict tracefs " Matthew Garrett
2019-04-04 13:39 ` Steven Rostedt
2019-04-04 20:09 ` Matthew Garrett
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