Libguestfs - Dec 2017 - [nbdkit PATCH v2] nbd: Fix memory leak

When converting from a single transaction to a linked list, I
forgot to free the storage for each member of the list.

Reported-by: Richard W.M. Jones <rjones@redhat.com>
Fixes: 7f5bb9bf13f041ea7702bda557d9dd668bc3423a
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 plugins/nbd/nbd.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/plugins/nbd/nbd.c b/plugins/nbd/nbd.c
index b844bf5..e79042c 100644
--- a/plugins/nbd/nbd.c
+++ b/plugins/nbd/nbd.c
@@ -311,6 +311,8 @@ nbd_reply_raw (struct handle *h, int *fd)
   struct reply rep;
   struct transaction **ptr;
   struct transaction *trans;
+  void *buf;
+  uint32_t count;

   *fd = -1;
   if (read_full (h->fd, &rep, sizeof rep) < 0)
@@ -334,9 +336,12 @@ nbd_reply_raw (struct handle *h, int *fd)
   }

   *fd = trans->u.fds[1];
+  buf = trans->buf;
+  count = trans->count;
+  free (trans);
   switch (be32toh (rep.error)) {
   case NBD_SUCCESS:
-    if (trans->buf && read_full (h->fd, trans->buf,
trans->count) < 0)
+    if (buf && read_full (h->fd, buf, count) < 0)
       return nbd_mark_dead (h);
     return 0;
   case NBD_EPERM:
@@ -399,6 +404,7 @@ nbd_reader (void *handle)
       abort ();
     }
     close (trans->u.fds[1]);
+    free (trans);
   }
   return NULL;
 }
-- 
2.14.3

On Sat, Dec 02, 2017 at 03:07:09PM -0600, Eric Blake
wrote:
> When converting from a single transaction to a linked list, I
> forgot to free the storage for each member of the list.
Thanks Eric.  This fixes the valgrind problem for me and I have pushed
it upstream.

Rich.

-- 
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