[PATCH] scsi: mpt3sas: Avoid freeing unallocated PCIe SGL buffers

_base_release_memory_pools() unconditionally frees every
ioc->pcie_sg_lookup[] entry, including ones the setup loop never
allocated after a partial failure, causing a "bad dma" warning on
debug kernels or a NULL pointer dereference otherwise.

Fixes: dbec4c9040ed ("scsi: mpt3sas: lockless command submission")
Reported-by: Laurence Oberman <[email protected]>
Signed-off-by: Chandrakanth Patil <[email protected]>
---
 drivers/scsi/mpt3sas/mpt3sas_base.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 79052f2accbd..11bcb8440e1c 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -5870,6 +5870,8 @@ _base_release_memory_pools(struct MPT3SAS_ADAPTER *ioc)
 
 	if (ioc->pcie_sgl_dma_pool) {
 		for (i = 0; i < ioc->scsiio_depth; i++) {
+			if (!ioc->pcie_sg_lookup[i].pcie_sgl)
+				continue;
 			dma_pool_free(ioc->pcie_sgl_dma_pool,
 					ioc->pcie_sg_lookup[i].pcie_sgl,
 					ioc->pcie_sg_lookup[i].pcie_sgl_dma);
-- 
2.52.0