[Qemu-devel] [PATCH] scsi-hd: fix property unset case

[Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>]

commit "BlockConf: Call backend functions to detect geometry and
blocksizes" causes a segmentation fault on the invalid configuration of
a scsi device without a drive.

Lets check for conf.blk before calling blkconf_blocksizes. The error
will be handled later on in scsi_realize anyway.

Reported-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
---
 hw/scsi/scsi-disk.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index 2921728..54d71f4 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -2291,7 +2291,12 @@ static void scsi_realize(SCSIDevice *dev, Error **errp)
 static void scsi_hd_realize(SCSIDevice *dev, Error **errp)
 {
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);
-    blkconf_blocksizes(&s->qdev.conf);
+    /* can happen for devices without drive. The error message for missing
+     * backend will be issued in scsi_realize
+     */
+    if (s->qdev.conf.blk) {
+        blkconf_blocksizes(&s->qdev.conf);
+    }
     s->qdev.blocksize = s->qdev.conf.logical_block_size;
     s->qdev.type = TYPE_DISK;
     if (!s->product) {
-- 
2.1.4