From: David Howells <dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: keyrings-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org,
matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org,
linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: [PATCH 11/16] x86: Lock down IO port access when the kernel is locked down
Date: Wed, 16 Nov 2016 21:48:36 +0000 [thread overview]
Message-ID: <147933291647.19316.6065544311010705130.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <147933283664.19316.12454053022687659937.stgit-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
From: Matthew Garrett <matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
IO port access would permit users to gain access to PCI configuration
registers, which in turn (on a lot of hardware) give access to MMIO register
space. This would potentially permit root to trigger arbitrary DMA, so lock
it down by default.
Signed-off-by: Matthew Garrett <matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org>
Signed-off-by: David Howells <dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
arch/x86/kernel/ioport.c | 5 +++--
drivers/char/mem.c | 4 ++++
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c
index 589b3193f102..2ee24e9ff6d8 100644
--- a/arch/x86/kernel/ioport.c
+++ b/arch/x86/kernel/ioport.c
@@ -15,6 +15,7 @@
#include <linux/thread_info.h>
#include <linux/syscalls.h>
#include <linux/bitmap.h>
+#include <linux/security.h>
#include <asm/syscalls.h>
/*
@@ -28,7 +29,7 @@ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
if ((from + num <= from) || (from + num > IO_BITMAP_BITS))
return -EINVAL;
- if (turn_on && !capable(CAP_SYS_RAWIO))
+ if (turn_on && (!capable(CAP_SYS_RAWIO) || kernel_is_locked_down()))
return -EPERM;
/*
@@ -108,7 +109,7 @@ SYSCALL_DEFINE1(iopl, unsigned int, level)
return -EINVAL;
/* Trying to gain more privileges? */
if (level > old) {
- if (!capable(CAP_SYS_RAWIO))
+ if (!capable(CAP_SYS_RAWIO) || kernel_is_locked_down())
return -EPERM;
}
regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) |
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 5bb1985ec484..17e22cb2db14 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -28,6 +28,7 @@
#include <linux/export.h>
#include <linux/io.h>
#include <linux/uio.h>
+#include <linux/security.h>
#include <linux/uaccess.h>
@@ -580,6 +581,9 @@ static ssize_t write_port(struct file *file, const char __user *buf,
unsigned long i = *ppos;
const char __user *tmp = buf;
+ if (kernel_is_locked_down())
+ return -EPERM;
+
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT;
while (count-- > 0 && i < 65536) {
next prev parent reply other threads:[~2016-11-16 21:48 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-16 21:47 [PATCH 00/16] Kernel lockdown David Howells
2016-11-16 21:47 ` [PATCH 01/16] Add the ability to lock down access to the running kernel image David Howells
[not found] ` <147933284407.19316.17886320817060158597.stgit-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-16 22:20 ` Borislav Petkov
2016-11-16 22:40 ` David Howells
2016-12-25 21:20 ` Pavel Machek
2016-12-25 21:44 ` David Howells
2016-11-16 21:47 ` [PATCH 02/16] efi: Get the secure boot status David Howells
2016-11-17 12:37 ` Lukas Wunner
2016-11-22 0:31 ` [PATCH 2/6] arm/efi: Allow invocation of arbitrary runtime services David Howells
2016-11-22 0:31 ` [PATCH 3/6] efi: Add SHIM and image security database GUID definitions David Howells
2016-11-22 0:32 ` [PATCH 4/6] efi: Get the secure boot status David Howells
2016-11-22 10:44 ` Lukas Wunner
[not found] ` <20161122104401.GC1552-JFq808J9C/izQB+pC5nmwQ@public.gmane.org>
2016-11-22 10:49 ` Ard Biesheuvel
2016-11-22 14:52 ` David Howells
[not found] ` <25371.1479826321-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-22 20:36 ` Lukas Wunner
2016-11-22 14:47 ` David Howells
2016-11-22 20:30 ` Lukas Wunner
2016-11-23 0:02 ` David Howells
[not found] ` <7199.1479826047-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-22 14:57 ` David Howells
2016-11-22 0:32 ` [PATCH 5/6] efi: Disable secure boot if shim is in insecure mode David Howells
2016-11-22 13:03 ` Lukas Wunner
2016-11-22 0:32 ` [PATCH 6/6] efi: Add EFI_SECURE_BOOT bit David Howells
2016-11-22 13:04 ` Lukas Wunner
2016-11-21 11:46 ` [PATCH 02/16] efi: Get the secure boot status David Howells
2016-11-21 19:58 ` Lukas Wunner
[not found] ` <20161117123731.GA11573-JFq808J9C/izQB+pC5nmwQ@public.gmane.org>
2016-11-21 11:42 ` David Howells
[not found] ` <29779.1479728545-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-21 11:52 ` Ard Biesheuvel
[not found] ` <CAKv+Gu-frVDhzORDRZ6XT+FxewsTgrxhXmM=DqaS6Ns4mJhQ9g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-11-21 12:41 ` David Howells
2016-11-21 13:14 ` Ard Biesheuvel
[not found] ` <CAKv+Gu8Lhm=u97hY1y+Y+Ladk=y7pSVNrow8ML1hQUJ9+74B-w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-11-21 15:17 ` Lukas Wunner
2016-11-21 15:25 ` Ard Biesheuvel
2016-11-22 0:31 ` [PATCH 1/6] x86/efi: Allow invocation of arbitrary runtime services David Howells
[not found] ` <147977469914.6360.17194649697208113702.stgit-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-22 10:20 ` Lukas Wunner
2016-11-22 14:17 ` David Howells
2016-11-22 14:58 ` Joe Perches
[not found] ` <1479826691.1942.11.camel-6d6DIl74uiNBDgjK7y7TUQ@public.gmane.org>
2016-11-22 15:52 ` David Howells
[not found] ` <24973.1479829961-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-22 16:25 ` Joe Perches
2016-11-22 16:40 ` David Howells
2016-11-22 16:51 ` Joe Perches
2016-11-16 21:47 ` [PATCH 03/16] efi: Disable secure boot if shim is in insecure mode David Howells
2016-11-16 21:47 ` [PATCH 04/16] efi: Lock down the kernel if booted in secure boot mode David Howells
2016-11-16 21:47 ` [PATCH 05/16] efi: Add EFI_SECURE_BOOT bit David Howells
2016-11-17 21:58 ` Ard Biesheuvel
2016-11-18 11:58 ` Josh Boyer
[not found] ` <CA+5PVA6F5qEnuL2UaXS9_fJ217J93cEZDDsz9Y2BPwHXcMdX-A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-11-18 12:10 ` Ard Biesheuvel
[not found] ` <CAKv+Gu_8r3oM-jvvuSiXTzxp0YMEVgc5KkScJ2UhGTaXm28L6w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-11-18 17:28 ` David Howells
2016-11-16 21:48 ` [PATCH 06/16] Add a sysrq option to exit secure boot mode David Howells
2016-11-16 21:48 ` [PATCH 07/16] kexec: Disable at runtime if the kernel is locked down David Howells
2016-11-16 21:48 ` [PATCH 08/16] Copy secure_boot flag in boot params across kexec reboot David Howells
2016-11-16 21:48 ` [PATCH 09/16] hibernate: Disable when the kernel is locked down David Howells
2016-11-16 21:48 ` [PATCH 10/16] PCI: Lock down BAR access " David Howells
[not found] ` <147933283664.19316.12454053022687659937.stgit-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-16 21:48 ` David Howells [this message]
2016-11-16 21:49 ` [PATCH 16/16] x86: Restrict MSR " David Howells
2016-11-16 22:27 ` [PATCH 00/16] Kernel lockdown One Thousand Gnomes
2016-11-21 19:53 ` Ard Biesheuvel
2016-11-30 14:27 ` One Thousand Gnomes
2016-11-16 21:48 ` [PATCH 12/16] ACPI: Limit access to custom_method when the kernel is locked down David Howells
2016-11-16 21:48 ` [PATCH 13/16] asus-wmi: Restrict debugfs interface " David Howells
2016-11-16 21:48 ` [PATCH 14/16] Restrict /dev/mem and /dev/kmem " David Howells
2016-11-16 21:49 ` [PATCH 15/16] acpi: Ignore acpi_rsdp kernel param when the kernel has been " David Howells
2016-11-16 22:28 ` [PATCH 00/16] Kernel lockdown Justin Forbes
2016-11-21 23:10 ` [PATCH] Lock down drivers that can have io ports, io mem, irqs and dma changed David Howells
2016-11-22 6:12 ` Dominik Brodowski
2016-11-23 12:58 ` David Howells
2016-11-23 19:21 ` Dominik Brodowski
[not found] ` <20161123192143.GA482-SGhQLRGLuNwb6pqDj42GsMgv3T4z79SOrE5yTffgRl4@public.gmane.org>
2016-11-24 17:34 ` David Howells
2016-11-24 20:19 ` Dominik Brodowski
2016-11-25 14:49 ` David Howells
[not found] ` <26173.1479769852-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-28 22:32 ` Corey Minyard
2016-11-29 0:11 ` David Howells
2016-11-29 0:23 ` Corey Minyard
2016-11-29 14:03 ` David Howells
[not found] ` <6973.1480428211-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-29 14:35 ` Corey Minyard
2016-11-30 14:41 ` One Thousand Gnomes
[not found] ` <20161130144105.2b6be4fe-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org>
2016-11-30 16:25 ` David Howells
2016-11-29 10:40 ` David Howells
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