linux-kernel - acpi: Fix broken error check in map

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 23 Sep 2016 17:08:04 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Dou Liyang <douly.fnst@...fujitsu.com>
cc:     cl@...ux.com, tj@...nel.org, mika.j.penttila@...il.com,
        mingo@...hat.com, akpm@...ux-foundation.org, rjw@...ysocki.net,
        hpa@...or.com, yasu.isimatu@...il.com,
        isimatu.yasuaki@...fujitsu.com, kamezawa.hiroyu@...fujitsu.com,
        izumi.taku@...fujitsu.com, gongzhaogang@...pur.com,
        len.brown@...el.com, lenb@...nel.org, chen.tang@...ystack.cn,
        rafael@...nel.org, x86@...nel.org, linux-acpi@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        Gu Zheng <guz.fnst@...fujitsu.com>,
        Tang Chen <tangchen@...fujitsu.com>,
        Zhu Guihua <zhugh.fnst@...fujitsu.com>
Subject: acpi: Fix broken error check in map_processor()

map_processor() checks the cpuid value returned by acpi_map_cpuid() for -1
but acpi_map_cpuid() returns -EINVAL in case of error.

As a consequence the error is ignored and the following access into percpu
data with that negative cpuid results in a boot crash.

This happens always when NR_CPUS/nr_cpu_ids is smaller than the number of
processors listed in the ACPI tables.

Use a proper error check for id < 0 so the function returns instead of
trying to map CPU#(-EINVAL).

Reported-by: Ingo Molnar <mingo@...nel.org>
Fixes: dc6db24d2476 ("x86/acpi: Set persistent cpuid <-> nodeid mapping when booting")
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
 drivers/acpi/processor_core.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -284,7 +284,7 @@ EXPORT_SYMBOL_GPL(acpi_get_cpuid);
 static bool __init
 map_processor(acpi_handle handle, phys_cpuid_t *phys_id, int *cpuid)
 {
-	int type;
+	int type, id;
 	u32 acpi_id;
 	acpi_status status;
 	acpi_object_type acpi_type;
@@ -320,10 +320,11 @@ map_processor(acpi_handle handle, phys_c
 	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
 
 	*phys_id = __acpi_get_phys_id(handle, type, acpi_id, false);
-	*cpuid = acpi_map_cpuid(*phys_id, acpi_id);
-	if (*cpuid == -1)
-		return false;
+	id = acpi_map_cpuid(*phys_id, acpi_id);
 
+	if (id < 0)
+		return false;
+	*cpuid = id;
 	return true;
 }