megaraid_sas: fix memory leak if SGL has zero length entries

commit 7a6a731bd00ca90d0e250867c3b9c05b5ff0fa49 upstream.

commit 98cb7e44 ([SCSI] megaraid_sas: Sanity check user
supplied length before passing it to dma_alloc_coherent())
introduced a memory leak.  Memory allocated for entries
following zero length SGL entries will not be freed.

Reference: http://bugs.debian.org/688198

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Acked-by: Adam Radford <aradford@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index 7c471eb..fc5a2ef 100644 (file)
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -4886,10 +4886,12 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance,
                                    sense, sense_handle);
        }
 
-       for (i = 0; i < ioc->sge_count && kbuff_arr[i]; i++) {
-               dma_free_coherent(&instance->pdev->dev,
-                                   kern_sge32[i].length,
-                                   kbuff_arr[i], kern_sge32[i].phys_addr);
+       for (i = 0; i < ioc->sge_count; i++) {
+               if (kbuff_arr[i])
+                       dma_free_coherent(&instance->pdev->dev,
+                                         kern_sge32[i].length,
+                                         kbuff_arr[i],
+                                         kern_sge32[i].phys_addr);
        }
 
        megasas_return_cmd(instance, cmd);