34 lines
1.3 KiB
Diff
34 lines
1.3 KiB
Diff
From: David Howells <dhowells@redhat.com>
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Date: Wed, 8 Nov 2017 15:11:36 +0000
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Subject: [23/29] x86/mmiotrace: Lock down the testmmiotrace module
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Origin: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/commit?id=20af3be0bcf6a78e3632770561fba6531dd3b444
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The testmmiotrace module shouldn't be permitted when the kernel is locked
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down as it can be used to arbitrarily read and write MMIO space.
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Suggested-by: Thomas Gleixner <tglx@linutronix.de>
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Signed-off-by: David Howells <dhowells@redhat.com
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cc: Thomas Gleixner <tglx@linutronix.de>
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cc: Steven Rostedt <rostedt@goodmis.org>
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cc: Ingo Molnar <mingo@kernel.org>
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cc: "H. Peter Anvin" <hpa@zytor.com>
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cc: x86@kernel.org
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---
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arch/x86/mm/testmmiotrace.c | 3 +++
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1 file changed, 3 insertions(+)
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diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c
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index f6ae6830b341..bbaad357f5d7 100644
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--- a/arch/x86/mm/testmmiotrace.c
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+++ b/arch/x86/mm/testmmiotrace.c
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@@ -115,6 +115,9 @@ static int __init init(void)
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{
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unsigned long size = (read_far) ? (8 << 20) : (16 << 10);
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+ if (kernel_is_locked_down("MMIO trace testing"))
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+ return -EPERM;
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+
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if (mmio_address == 0) {
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pr_err("you have to use the module argument mmio_address.\n");
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pr_err("DO NOT LOAD THIS MODULE UNLESS YOU REALLY KNOW WHAT YOU ARE DOING!\n");
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