[PATCH] mpt3sas: Ensure the connector_name string is NUL-terminated

From: Calvin Owens
Date: Thu Jul 28 2016 - 00:46:15 EST


We blindly trust the hardware to give us NUL-terminated strings, which
is a bad idea because it doesn't always do that. For example:

[ 481.184784] mpt3sas_cm0: enclosure level(0x0000), connector name( \x3)

In this case, connector_name is four spaces. We got lucky here because
the 2nd byte beyond our character array happens to be a NUL. Fix this
by explicitly writing '\0' to the end of the string to ensure we don't
run off the edge of the world in printk().

Signed-off-by: Calvin Owens <calvinowens@xxxxxx>
---
drivers/scsi/mpt3sas/mpt3sas_base.h | 2 +-
drivers/scsi/mpt3sas/mpt3sas_scsih.c | 10 ++++++----
2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.h b/drivers/scsi/mpt3sas/mpt3sas_base.h
index 892c9be..eb7f5b0 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.h
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.h
@@ -478,7 +478,7 @@ struct _sas_device {
u8 pfa_led_on;
u8 pend_sas_rphy_add;
u8 enclosure_level;
- u8 connector_name[4];
+ u8 connector_name[5];
struct kref refcount;
};

diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index cd91a68..acabe48 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -5380,8 +5380,9 @@ _scsih_check_device(struct MPT3SAS_ADAPTER *ioc,
MPI2_SAS_DEVICE0_FLAGS_ENCL_LEVEL_VALID) {
sas_device->enclosure_level =
le16_to_cpu(sas_device_pg0.EnclosureLevel);
- memcpy(&sas_device->connector_name[0],
- &sas_device_pg0.ConnectorName[0], 4);
+ memcpy(sas_device->connector_name,
+ sas_device_pg0.ConnectorName, 4);
+ sas_device->connector_name[4] = '\0';
} else {
sas_device->enclosure_level = 0;
sas_device->connector_name[0] = '\0';
@@ -5508,8 +5509,9 @@ _scsih_add_device(struct MPT3SAS_ADAPTER *ioc, u16 handle, u8 phy_num,
if (sas_device_pg0.Flags & MPI2_SAS_DEVICE0_FLAGS_ENCL_LEVEL_VALID) {
sas_device->enclosure_level =
le16_to_cpu(sas_device_pg0.EnclosureLevel);
- memcpy(&sas_device->connector_name[0],
- &sas_device_pg0.ConnectorName[0], 4);
+ memcpy(sas_device->connector_name,
+ sas_device_pg0.ConnectorName, 4);
+ sas_device->connector_name[4] = '\0';
} else {
sas_device->enclosure_level = 0;
sas_device->connector_name[0] = '\0';
--
2.8.0.rc2