[PULL 02/11] block/vmdk: Avoid assertion if image file has no extents

[Kevin Wolf <kwolf@redhat.com>]

From: Peter Maydell <peter.maydell@linaro.org>

On a malformed image file which has no extents in it, we will open the file
but then fall over on an assertion in vmdk_co_get_info():

    $ cat bad.vmdk
    # Disk DescriptorFile
    version=1
    CID=fffffffe
    parentCID=ffffffff
    createType="vmfs"

    $ qemu-img info -f vmdk /tmp/zz9
    qemu-img: ../../block/vmdk.c:3104: int vmdk_co_get_info(BlockDriverState *, BlockDriverInfo *): Assertion `s->num_extents' failed.
    Aborted (core dumped)

(This was noted in passing in the report of #4571.)

Cc: qemu-stable@nongnu.org
Fixes: 7fa60fa3778f1c7336 ("VMDK: open/read/write for monolithicFlat image")
Reported-by: router0mail <https://gitlab.com/router0mail>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-ID: <20261103143516.2182626-2-peter.maydell@linaro.org>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/vmdk.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/block/vmdk.c b/block/vmdk.c
index b6e78a2b5d9..86059e1fa08 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1301,6 +1301,12 @@ vmdk_parse_extents(const char *desc, BlockDriverState *bs, QDict *options,
         extent->type = g_strdup(type);
     }
 
+    if (s->num_extents == 0) {
+        error_setg(errp, "Invalid file: no extent lines present");
+        ret = -EINVAL;
+        goto out;
+    }
+
     ret = 0;
     goto out;
 
-- 
2.56.0