[PATCH AUTOSEL 5.4 162/330] cpu-topology: Fix the potential data corruption

From: Sasha Levin
Date: Thu Sep 17 2020 - 22:04:38 EST

From: Zeng Tao <prime.zeng@xxxxxxxxxxxxx>

[ Upstream commit 4a33691c4cea9eb0a7c66e87248be4637e14b180 ]

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@xxxxxxx>
Signed-off-by: Zeng Tao <prime.zeng@xxxxxxxxxxxxx>

Link: https://lore.kernel.org/r/1583294092-5929-1-git-send-email-prime.zeng@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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 1eb81f113786f..83e26fd188cc9 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -270,7 +270,7 @@ 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;
@@ -317,7 +317,7 @@ 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;