From 4c2bbd5e6f7b1c1823376c708034cd8dced8eb8b Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 18 Feb 2019 12:45:01 +0000 Subject: [PATCH] x86/mmiotrace: Lock down the testmmiotrace module The testmmiotrace module shouldn't be permitted when the kernel is locked down as it can be used to arbitrarily read and write MMIO space. Suggested-by: Thomas Gleixner Signed-off-by: David Howells cc: Steven Rostedt cc: Ingo Molnar cc: "H. Peter Anvin" cc: x86@kernel.org Gbp-Pq: Topic features/all/lockdown Gbp-Pq: Name 0022-x86-mmiotrace-Lock-down-the-testmmiotrace-module.patch --- arch/x86/mm/testmmiotrace.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c index 0881e1ff1e5..13f1da99ee5 100644 --- a/arch/x86/mm/testmmiotrace.c +++ b/arch/x86/mm/testmmiotrace.c @@ -116,6 +116,9 @@ static int __init init(void) { unsigned long size = (read_far) ? (8 << 20) : (16 << 10); + if (kernel_is_locked_down("MMIO trace testing")) + return -EPERM; + if (mmio_address == 0) { pr_err("you have to use the module argument mmio_address.\n"); pr_err("DO NOT LOAD THIS MODULE UNLESS YOU REALLY KNOW WHAT YOU ARE DOING!\n"); -- 2.30.2