[SCSI] libsas: Fix potential NULL dereference in sas_smp_get_phy_events()

In sas_smp_get_phy_events() we never test if the call to
alloc_smp_req(RPEL_REQ_SIZE) succeeds or fails. That means we run
the risk of dereferencing a NULL pointer if it does fail. Far
better to test if we got NULL back and in that case return -ENOMEM
just as we already do for the other memory allocation in that
function.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 8603ae65213d..8727436b222d 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -507,14 +507,21 @@ static int sas_dev_present_in_domain(struct asd_sas_port *port,
 int sas_smp_get_phy_events(struct sas_phy *phy)
 {
         int res;
+        u8 *req;
+        u8 *resp;
         struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
         struct domain_device *dev = sas_find_dev_by_rphy(rphy);
-        u8 *req = alloc_smp_req(RPEL_REQ_SIZE);
-        u8 *resp = kzalloc(RPEL_RESP_SIZE, GFP_KERNEL);
 
-        if (!resp)
+        req = alloc_smp_req(RPEL_REQ_SIZE);
+        if (!req)
                 return -ENOMEM;
 
+        resp = alloc_smp_resp(RPEL_RESP_SIZE);
+        if (!resp) {
+                kfree(req);
+                return -ENOMEM;
+        }
+
         req[1] = SMP_REPORT_PHY_ERR_LOG;
         req[9] = phy->number;