From 96534bdb32aaffb2cdaa30794233fdf8c6ace3b7 Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland@arm.com>
Date: Mon, 23 Apr 2018 11:41:33 +0100
Subject: [PATCH] arm64: add sentinel to kpti_safe_list

Git-commit: 71c751f2a43fa03fae3cf5f0067ed3001a397013
Patch-mainline: v4.17-rc3
References: fate#325862

We're missing a sentinel entry in kpti_safe_list. Thus is_midr_in_range_list()
can walk past the end of kpti_safe_list. Depending on the contents of memory,
this could erroneously match a CPU's MIDR, cause a data abort, or other bad
outcomes.

Add the sentinel entry to avoid this.

Fixes: be5b299830c63ed7 ("arm64: capabilities: Add support for checks based on a list of MIDRs")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
 arch/arm64/kernel/cpufeature.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 379a4a9f..bd3c82bf 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -868,6 +868,7 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
 	static const struct midr_range kpti_safe_list[] = {
 		MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
 		MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
+		{ /* sentinel */ }
 	};
 	char const *str = "command line option";
 
-- 
2.11.0