[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>

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 8603ae6..8727436 100644 (file)
--- 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;