[Qemu-devel] [PATCH RFC v2 2/9] rbd: Fix to cleanly reject -drive without pool or image

[Markus Armbruster <armbru@redhat.com>]

qemu_rbd_open() neglects to check pool and image are present.
Reproducer:

    $ qemu-system-x86_64 -nodefaults -drive if=none,driver=rbd,pool=p
    Segmentation fault (core dumped)
    $ qemu-system-x86_64 -nodefaults -drive if=none,driver=rbd,image=i
    qemu-system-x86_64: -drive if=none,driver=rbd,image=i: error opening pool (null)

Doesn't affect -drive with file=..., because qemu_rbd_parse_filename()
always sets both pool and image.

Doesn't affect -blockdev, because pool and image are mandatory in the
QAPI schema.

Fix by adding the missing checks.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 block/rbd.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/block/rbd.c b/block/rbd.c
index ee13f3d..5ba2a87 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -711,6 +711,12 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags,
     name           = qemu_opt_get(opts, "image");
     keypairs       = qemu_opt_get(opts, "keyvalue-pairs");
 
+    if (!pool || !name) {
+        error_setg(errp, "Parameters 'pool' and 'image' are required");
+        r = -EINVAL;
+        goto failed_opts;
+    }
+
     r = rados_create(&s->cluster, clientname);
     if (r < 0) {
         error_setg_errno(errp, -r, "error initializing");
@@ -718,9 +724,7 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags,
     }
 
     s->snap = g_strdup(snap);
-    if (name) {
-        pstrcpy(s->name, RBD_MAX_IMAGE_NAME_SIZE, name);
-    }
+    pstrcpy(s->name, RBD_MAX_IMAGE_NAME_SIZE, name);
 
     /* try default location when conf=NULL, but ignore failure */
     r = rados_conf_read_file(s->cluster, conf);
-- 
2.7.4