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From:   Zeng Tao <prime.zeng@hisilicon.com>
To:     <sudeep.holla@arm.com>
CC:     <linuxarm@huawei.com>, Zeng Tao <prime.zeng@hisilicon.com>,
        "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: [PATCH v2] cpu-topology: Fix the potential data corruption
Date:   Wed, 4 Mar 2020 11:54:52 +0800
Message-ID: <1583294092-5929-1-git-send-email-prime.zeng@hisilicon.com>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Currently there are only 10 bytes to store the cpu-topology 'name'
information. Only 10 bytes copied into cluster/thread/core names.

If the cluster ID exceeds 2-digit number, it will result in the data
corruption, and ending up in a dead loop in the parsing routines. The
same applies to the thread names with more that 3-digit number.

This issue was found using the boundary tests under virtualised
environment like QEMU.

Let us increase the buffer to fix such potential issues.

Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com>

---
Changelog:
v1->v2: update the commit message suggested by sudeep.
---
 drivers/base/arch_topology.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 6119e11..f489883 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -281,7 +281,7 @@ static int __init get_cpu_for_node(struct device_node *node)
 static int __init parse_core(struct device_node *core, int package_id,
 			     int core_id)
 {
-	char name[10];
+	char name[20];
 	bool leaf = true;
 	int i = 0;
 	int cpu;
@@ -327,7 +327,7 @@ static int __init parse_core(struct device_node *core, int package_id,
 
 static int __init parse_cluster(struct device_node *cluster, int depth)
 {
-	char name[10];
+	char name[20];
 	bool leaf = true;
 	bool has_cores = false;
 	struct device_node *c;
-- 
2.8.1