[Qemu-block] [PATCH] block/iscsi: avoid potential overflow of acb->task->cdb

[Peter Lieven]

at least in the path via virtio-blk the maximum size is not
restricted.

Cc: address@hidden
Signed-off-by: Peter Lieven <address@hidden>
---
 block/iscsi.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/block/iscsi.c b/block/iscsi.c
index 2ca8e72..e7d5f7b 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -833,6 +833,13 @@ static BlockAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
         return &acb->common;
     }
 
+    if (acb->ioh->cmd_len > SCSI_CDB_MAX_SIZE) {
+        error_report("iSCSI: ioctl error CDB exceeds max size (%d > %d)",
+                     acb->ioh->cmd_len, SCSI_CDB_MAX_SIZE);
+        qemu_aio_unref(acb);
+        return NULL;
+    }
+
     acb->task = malloc(sizeof(struct scsi_task));
     if (acb->task == NULL) {
         error_report("iSCSI: Failed to allocate task for scsi command. %s",
-- 
1.9.1