2019-07-29 03:44:18

by Jia-Ju Bai

[permalink] [raw]
Subject: [PATCH] scsi: mpt3sas: Fix a possible null-pointer dereference in mpt3sas_transport_update_links()

In mpt3sas_transport_update_links(), there is an if statement
on line 994 to check whether mpt3sas_phy->phy is NULL:
if (mpt3sas_phy->phy)

When mpt3sas_phy->phy is NULL, it is used on line 999:
dev_printk(KERN_INFO, &mpt3sas_phy->phy->dev, ...)

Thus, a possible null-pointer dereference may occur.

To fix this bug, mpt3sas_phy->phy is checked before being used.

This bug is found by a static analysis tool STCheck written by us.

Signed-off-by: Jia-Ju Bai <[email protected]>
---
drivers/scsi/mpt3sas/mpt3sas_transport.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_transport.c b/drivers/scsi/mpt3sas/mpt3sas_transport.c
index 5324662751bf..df790a9877a0 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_transport.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_transport.c
@@ -995,7 +995,8 @@ mpt3sas_transport_update_links(struct MPT3SAS_ADAPTER *ioc,
mpt3sas_phy->phy->negotiated_linkrate =
_transport_convert_phy_link_rate(link_rate);

- if ((ioc->logging_level & MPT_DEBUG_TRANSPORT))
+ if ((ioc->logging_level & MPT_DEBUG_TRANSPORT) &&
+ mpt3sas_phy->phy)
dev_printk(KERN_INFO, &mpt3sas_phy->phy->dev,
"refresh: parent sas_addr(0x%016llx),\n"
"\tlink_rate(0x%02x), phy(%d)\n"
--
2.17.0