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 <[email protected]> Reported-by: Boris Ostrovsky <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
ambv · Dec 27, 2016 · 0dad3a3 · 0dad3a3
1 parent b9d9d69
commit 0dad3a3
Showing 1 changed file with 3 additions and 0 deletions.
diff --git 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));