From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 26 Dec 2016 21:58:20 +0000 (+0100)
Subject: x86/mce/AMD: Make the init code more robust
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=0dad3a3014a0b9e72521ff44f17e0054f43dcdea;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

x86/mce/AMD: Make the init code more robust

If mce_device_init() fails then the mce device pointer is NULL and the
AMD mce code happily dereferences it.

Add a sanity check.

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index ffacfdcacb85..a5fd137417a2 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -1182,6 +1182,9 @@ static int threshold_create_bank(unsigned int cpu, unsigned int bank)
 	const char *name = get_name(bank, NULL);
 	int err = 0;
 
+	if (!dev)
+		return -ENODEV;
+
 	if (is_shared_bank(bank)) {
 		nb = node_to_amd_nb(amd_get_nb_id(cpu));