File CVE-2017-9503-qemuu-megasas-always-store-SCSIRequest-into-MegasasCmd.patch of Package xen.6121

This ensures that the request is unref'ed properly, and avoids a
segmentation fault in the new qtest testcase that is added.

Reported-by: Zhangyanyu <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
 hw/scsi/megasas.c    | 31 ++++++++++++++++---------------
 tests/megasas-test.c | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 15 deletions(-)

Index: xen-4.4.4-testing/tools/qemu-xen-dir-remote/hw/scsi/megasas.c
===================================================================
--- xen-4.4.4-testing.orig/tools/qemu-xen-dir-remote/hw/scsi/megasas.c
+++ xen-4.4.4-testing/tools/qemu-xen-dir-remote/hw/scsi/megasas.c
@@ -562,6 +562,9 @@ static void megasas_reset_frames(Megasas
 
 static void megasas_abort_command(MegasasCmd *cmd)
 {
+    if (cmd->dcmd_opcode != -1) {
+        return;
+    }
     if (cmd->req) {
         scsi_req_cancel(cmd->req);
         cmd->req = NULL;
@@ -965,7 +968,6 @@ static int megasas_pd_get_info_submit(SC
     uint64_t pd_size;
     uint16_t sdev_id = ((sdev->id & 0xFF) >> 8) | (lun & 0xFF);
     uint8_t cmdbuf[6];
-    SCSIRequest *req;
     size_t len, resid;
 
     if (!cmd->iov_buf) {
@@ -975,8 +977,8 @@ static int megasas_pd_get_info_submit(SC
         info->inquiry_data[0] = 0x7f; /* Force PQual 0x3, PType 0x1f */
         info->vpd_page83[0] = 0x7f;
         megasas_setup_inquiry(cmdbuf, 0, sizeof(info->inquiry_data));
-        req = scsi_req_new(sdev, cmd->index, lun, cmdbuf, cmd);
-        if (!req) {
+        cmd->req = scsi_req_new(sdev, cmd->index, lun, cmdbuf, cmd);
+        if (!cmd->req) {
             trace_megasas_dcmd_req_alloc_failed(cmd->index,
                                                 "PD get info std inquiry");
             g_free(cmd->iov_buf);
@@ -985,26 +987,26 @@ static int megasas_pd_get_info_submit(SC
         }
         trace_megasas_dcmd_internal_submit(cmd->index,
                                            "PD get info std inquiry", lun);
-        len = scsi_req_enqueue(req);
+        len = scsi_req_enqueue(cmd->req);
         if (len > 0) {
             cmd->iov_size = len;
-            scsi_req_continue(req);
+            scsi_req_continue(cmd->req);
         }
         return MFI_STAT_INVALID_STATUS;
     } else if (info->inquiry_data[0] != 0x7f && info->vpd_page83[0] == 0x7f) {
         megasas_setup_inquiry(cmdbuf, 0x83, sizeof(info->vpd_page83));
-        req = scsi_req_new(sdev, cmd->index, lun, cmdbuf, cmd);
-        if (!req) {
+        cmd->req = scsi_req_new(sdev, cmd->index, lun, cmdbuf, cmd);
+        if (!cmd->req) {
             trace_megasas_dcmd_req_alloc_failed(cmd->index,
                                                 "PD get info vpd inquiry");
             return MFI_STAT_FLASH_ALLOC_FAIL;
         }
         trace_megasas_dcmd_internal_submit(cmd->index,
                                            "PD get info vpd inquiry", lun);
-        len = scsi_req_enqueue(req);
+        len = scsi_req_enqueue(cmd->req);
         if (len > 0) {
             cmd->iov_size = len;
-            scsi_req_continue(req);
+            scsi_req_continue(cmd->req);
         }
         return MFI_STAT_INVALID_STATUS;
     }
@@ -1112,7 +1114,6 @@ static int megasas_ld_get_info_submit(SC
     struct mfi_ld_info *info = cmd->iov_buf;
     size_t dcmd_size = sizeof(struct mfi_ld_info);
     uint8_t cdb[6];
-    SCSIRequest *req;
     ssize_t len, resid;
     BlockConf *conf = &sdev->conf;
     uint16_t sdev_id = ((sdev->id & 0xFF) >> 8) | (lun & 0xFF);
@@ -1123,8 +1124,8 @@ static int megasas_ld_get_info_submit(SC
         memset(cmd->iov_buf, 0x0, dcmd_size);
         info = cmd->iov_buf;
         megasas_setup_inquiry(cdb, 0x83, sizeof(info->vpd_page83));
-        req = scsi_req_new(sdev, cmd->index, lun, cdb, cmd);
-        if (!req) {
+        cmd->req = scsi_req_new(sdev, cmd->index, lun, cdb, cmd);
+        if (!cmd->req) {
             trace_megasas_dcmd_req_alloc_failed(cmd->index,
                                                 "LD get info vpd inquiry");
             g_free(cmd->iov_buf);
@@ -1133,10 +1134,10 @@ static int megasas_ld_get_info_submit(SC
         }
         trace_megasas_dcmd_internal_submit(cmd->index,
                                            "LD get info vpd inquiry", lun);
-        len = scsi_req_enqueue(req);
+        len = scsi_req_enqueue(cmd->req);
         if (len > 0) {
             cmd->iov_size = len;
-            scsi_req_continue(req);
+            scsi_req_continue(cmd->req);
         }
         return MFI_STAT_INVALID_STATUS;
     }
@@ -1739,7 +1740,7 @@ static void megasas_command_complete(SCS
 
     trace_megasas_command_complete(cmd->index, status, resid);
 
-    if (cmd->req != req) {
+    if (cmd->dcmd_opcode != -1) {
         /*
          * Internal command complete
          */