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From: dhowells@redhat.com (David Howells)
To: linux-security-module@vger.kernel.org
Subject: [PATCH 12/30] x86: Lock down IO port access when the kernel is locked down
Date: Thu,  9 Nov 2017 17:32:07 +0000	[thread overview]
Message-ID: <151024872783.28329.827291504646744307.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <151024863544.28329.2436580122759221600.stgit@warthog.procyon.org.uk>

From: Matthew Garrett <matthew.garrett@nebula.com>

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.

This also implicitly locks down the KDADDIO, KDDELIO, KDENABIO and
KDDISABIO console ioctls.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: "Lee, Chun-Yi" <jlee@suse.com>
cc: x86 at kernel.org
---

 arch/x86/kernel/ioport.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c
index 9c3cf0944bce..2c0f058651c5 100644
--- a/arch/x86/kernel/ioport.c
+++ b/arch/x86/kernel/ioport.c
@@ -30,7 +30,8 @@ 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("ioperm")))
 		return -EPERM;
 
 	/*
@@ -120,7 +121,8 @@ 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("iopl"))
 			return -EPERM;
 	}
 	regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) |

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  parent reply	other threads:[~2017-11-09 17:32 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-09 17:30 [PATCH 00/30] security, efi: Add kernel lockdown David Howells
2017-11-09 17:30 ` [PATCH 01/30] Add the ability to lock down access to the running kernel image David Howells
2017-11-09 17:30 ` [PATCH 02/30] Add a SysRq option to lift kernel lockdown David Howells
2017-11-09 17:31 ` [PATCH 03/30] ima: require secure_boot rules in lockdown mode David Howells
2017-11-09 17:31 ` [PATCH 04/30] Enforce module signatures if the kernel is locked down David Howells
2017-11-09 17:31 ` [PATCH 05/30] Restrict /dev/{mem, kmem, port} when " David Howells
2017-11-09 17:31 ` [PATCH 06/30] kexec: Disable at runtime if " David Howells
2017-11-09 17:31 ` [PATCH 07/30] Copy secure_boot flag in boot params across kexec reboot David Howells
2017-11-09 17:31 ` [PATCH 08/30] kexec_file: Restrict at runtime if the kernel is locked down David Howells
2018-01-11 11:59   ` Jiri Bohac
2018-01-11 12:01     ` [PATCH 08a/30] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Jiri Bohac
2018-01-11 12:02     ` [PATCH 08b/30] kexec_file: Restrict at runtime if the kernel is locked down Jiri Bohac
2018-01-16 16:31     ` [PATCH 08a/30] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE David Howells
2018-01-16 19:39       ` Jiri Bohac
2018-01-17 16:34       ` David Howells
2018-01-19 12:54         ` Jiri Bohac
2018-02-21 16:20         ` David Howells
2018-01-11 12:43   ` [PATCH 08/30] kexec_file: Restrict at runtime if the kernel is locked down David Howells
2018-01-11 12:47   ` David Howells
2018-01-11 15:44     ` Jiri Bohac
2018-01-17 16:16     ` David Howells
2017-11-09 17:31 ` [PATCH 09/30] hibernate: Disable when " David Howells
2017-11-09 17:31 ` [PATCH 10/30] uswsusp: " David Howells
2017-11-09 17:32 ` [PATCH 11/30] PCI: Lock down BAR access " David Howells
2017-11-09 17:32 ` David Howells [this message]
2017-11-09 17:32 ` [PATCH 13/30] x86/msr: Restrict MSR " David Howells
2017-11-09 17:32 ` [PATCH 14/30] asus-wmi: Restrict debugfs interface " David Howells
2017-11-09 17:32 ` [PATCH 15/30] ACPI: Limit access to custom_method " David Howells
2017-11-09 17:32 ` [PATCH 16/30] acpi: Ignore acpi_rsdp kernel param when the kernel has been " David Howells
2017-11-09 17:32 ` [PATCH 17/30] acpi: Disable ACPI table override if the kernel is " David Howells
2017-11-09 17:32 ` [PATCH 18/30] acpi: Disable APEI error injection " David Howells
2019-11-07  8:21   ` Joey Lee
2022-05-28  0:11     ` joeyli
2017-11-09 17:33 ` [PATCH 19/30] scsi: Lock down the eata driver David Howells
2017-11-09 17:33 ` [PATCH 20/30] Prohibit PCMCIA CIS storage when the kernel is locked down David Howells
2017-11-09 17:33 ` [PATCH 21/30] Lock down TIOCSSERIAL David Howells
2017-11-09 17:33 ` [PATCH 22/30] Lock down module params that specify hardware parameters (eg. ioport) David Howells
2017-11-09 17:33 ` [PATCH 23/30] x86/mmiotrace: Lock down the testmmiotrace module David Howells
2017-11-09 17:33 ` [PATCH 24/30] debugfs: Disallow use of debugfs files when the kernel is locked down David Howells
2017-11-09 17:33 ` [PATCH 25/30] Lock down /proc/kcore David Howells
2017-11-09 17:33 ` [PATCH 26/30] Lock down ftrace David Howells
2017-11-10  9:23   ` Jiri Kosina
2017-11-10 10:07   ` David Howells
2017-11-10 10:15     ` Jiri Kosina
2017-11-10 10:21     ` David Howells
2017-11-10 10:23       ` Jiri Kosina
2017-11-10 11:06       ` David Howells
2017-11-09 17:34 ` [PATCH 27/30] Lock down kprobes David Howells
2017-11-09 17:34 ` [PATCH 28/30] bpf: Restrict kernel image access functions when the kernel is locked down David Howells
2017-11-09 17:34 ` [PATCH 29/30] efi: Add an EFI_SECURE_BOOT flag to indicate secure boot mode David Howells
2017-11-09 17:34 ` [PATCH 30/30] efi: Lock down the kernel if booted in " David Howells
2018-02-22 13:07 ` [PATCH 04/30] Enforce module signatures if the kernel is locked down David Howells
2018-02-22 18:44   ` Jiri Bohac
2018-02-22 14:20 ` [PATCH 08/30] kexec_file: Restrict at runtime " David Howells
2018-02-22 19:08   ` Jiri Bohac
2018-02-22 14:21 ` David Howells
2018-02-22 19:14   ` Jiri Bohac
2018-03-03  1:18 ` [PATCH 00/30] security, efi: Add kernel lockdown Andrew Morton

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