mpt3sas: set num_phys after allocating phy[] space

In _scsih_sas_host_add, the number of HBA phys are determined and then
later used to allocate an array of struct _sas_phy's.  If the routine
sets ioc->sas_hba.num_phys, but then fails to allocate the
ioc->sas_hba.phy array (by kcalloc error or other intermediate
error/exit path), ioc->sas_hba is left in a dangerous state: all readers
of ioc->sas_hba.phy[] do so by indexing it from 0..ioc->sas_hba.num_phys
without checking that the space was ever allocated.

Modify _scsih_sas_host_add to set ioc->sas_hba.num_phys only after
successfully allocating ioc->sas_hba.phy[].

Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index 6bff13e..cd6be7b 100644 (file)
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -4903,13 +4903,22 @@ _scsih_sas_host_add(struct MPT3SAS_ADAPTER *ioc)
        u16 ioc_status;
        u16 sz;
        u8 device_missing_delay;
+       u8 num_phys;
 
-       mpt3sas_config_get_number_hba_phys(ioc, &ioc->sas_hba.num_phys);
-       if (!ioc->sas_hba.num_phys) {
+       mpt3sas_config_get_number_hba_phys(ioc, &num_phys);
+       if (!num_phys) {
                pr_err(MPT3SAS_FMT "failure at %s:%d/%s()!\n",
                    ioc->name, __FILE__, __LINE__, __func__);
                return;
        }
+       ioc->sas_hba.phy = kcalloc(num_phys,
+           sizeof(struct _sas_phy), GFP_KERNEL);
+       if (!ioc->sas_hba.phy) {
+               pr_err(MPT3SAS_FMT "failure at %s:%d/%s()!\n",
+                   ioc->name, __FILE__, __LINE__, __func__);
+               goto out;
+       }
+       ioc->sas_hba.num_phys = num_phys;
 
        /* sas_iounit page 0 */
        sz = offsetof(Mpi2SasIOUnitPage0_t, PhyData) + (ioc->sas_hba.num_phys *
@@ -4969,13 +4978,6 @@ _scsih_sas_host_add(struct MPT3SAS_ADAPTER *ioc)
                    MPI2_SASIOUNIT1_REPORT_MISSING_TIMEOUT_MASK;
 
        ioc->sas_hba.parent_dev = &ioc->shost->shost_gendev;
-       ioc->sas_hba.phy = kcalloc(ioc->sas_hba.num_phys,
-           sizeof(struct _sas_phy), GFP_KERNEL);
-       if (!ioc->sas_hba.phy) {
-               pr_err(MPT3SAS_FMT "failure at %s:%d/%s()!\n",
-                   ioc->name, __FILE__, __LINE__, __func__);
-               goto out;
-       }
        for (i = 0; i < ioc->sas_hba.num_phys ; i++) {
                if ((mpt3sas_config_get_phy_pg0(ioc, &mpi_reply, &phy_pg0,
                    i))) {