1 files changed, 20 insertions, 2 deletions

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index e6fc716aca45..f533f3375e24 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -192,7 +192,8 @@ static int sock_xmit(struct nbd_device *lo, int send, void *buf, int size,
                         if (lo->xmit_timeout)
                                 del_timer_sync(&ti);
                 } else
-                        result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0);
+                        result = kernel_recvmsg(sock, &msg, &iov, 1, size,
+                                                msg.msg_flags);
 
                 if (signal_pending(current)) {
                         siginfo_t info;
@@ -753,9 +754,26 @@ static int __init nbd_init(void)
                 return -ENOMEM;
 
         part_shift = 0;
-        if (max_part > 0)
+        if (max_part > 0) {
                 part_shift = fls(max_part);
 
+                /*
+                 * Adjust max_part according to part_shift as it is exported
+                 * to user space so that user can know the max number of
+                 * partition kernel should be able to manage.
+                 *
+                 * Note that -1 is required because partition 0 is reserved
+                 * for the whole disk.
+                 */
+                max_part = (1UL << part_shift) - 1;
+        }
+
+        if ((1UL << part_shift) > DISK_MAX_PARTS)
+                return -EINVAL;
+
+        if (nbds_max > 1UL << (MINORBITS - part_shift))
+                return -EINVAL;
+
         for (i = 0; i < nbds_max; i++) {
                 struct gendisk *disk = alloc_disk(1 << part_shift);
                 if (!disk)