[PATCH v3 5/7] mptsas: do not crash QEMU on migration errors

[Laurent Vivier <lvivier@redhat.com>]

From: "Michael S. Tsirkin" <mst@redhat.com>

Currently mptsas asserts on invalid sg list count in the migration
stream.

Fail migration gracefully instead.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
[lvivier: use errp rather than qemu_file_set_error() to report error]
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---

Notes:
    v2: new patch from Michael S. Tsirkin
        https://lore.kernel.org/qemu-devel/258d84f5af807e0103bf6f59165dd7450918e58c.1784898250.git.mst@redhat.com/
        Modified to use errp parameter with error_setg() instead of
        qemu_file_set_error() to report error

 hw/scsi/mptsas.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/hw/scsi/mptsas.c b/hw/scsi/mptsas.c
index 45638af0afc3..34ceb6b5d25e 100644
--- a/hw/scsi/mptsas.c
+++ b/hw/scsi/mptsas.c
@@ -36,6 +36,8 @@
 #include "qapi/error.h"
 #include "mptsas.h"
 #include "migration/qemu-file-types.h"
+#include "migration/qemu-file.h"
+#include "qemu/error-report.h"
 #include "migration/vmstate.h"
 #include "mpi.h"
 
@@ -1242,12 +1244,12 @@ static void *mptsas_load_request(QEMUFile *f, SCSIRequest *sreq, Error **errp)
     qemu_get_buffer(f, (unsigned char *)&req->scsi_io, sizeof(req->scsi_io));
 
     n = qemu_get_be32(f);
-    /* TODO: add a way for SCSIBusInfo's load_request to fail,
-     * and fail migration instead of asserting here.
-     * This is just one thing (there are probably more) that must be
-     * fixed before we can allow NDEBUG compilation.
-     */
-    assert(n >= 0);
+    if (n < 0) {
+        error_setg(errp, "mptsas: invalid sg list count %d in migration stream",
+                   n);
+        g_free(req);
+        return NULL;
+    }
 
     pci_dma_sglist_init(&req->qsg, pci, n);
     for (i = 0; i < n; i++) {
-- 
2.54.0