commit 8585afd8133eed037dde9c14106e7eb8d7c46968
author Max Reitz <mreitz@redhat.com> Wed Sep 25 16:37:18 2013 +0200
committer Kevin Wolf <kwolf@redhat.com> Fri Sep 27 11:31:59 2013 +0200
tree 3fd41ce93be9bbc8e7e79c646b8ac8e6fd86ae00
parent fd9e03e6060b3a64099d17e4a886421b21dd7341

qcow2: Don't put invalid L2 table into cache

In l2_allocate, the fail path is executed if qcow2_cache_flush fails.
However, the L2 table has not yet been fetched from the L2 table cache.
The qcow2_cache_put in the fail path therefore basically gives an
undefined argument as the L2 table address (in this case).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/qcow2-cluster.c

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index ffa8941..153ea50 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -188,7 +188,7 @@
 {
     BDRVQcowState *s = bs->opaque;
     uint64_t old_l2_offset;
-    uint64_t *l2_table;
+    uint64_t *l2_table = NULL;
     int64_t l2_offset;
     int ret;
 
@@ -265,7 +265,9 @@
 
 fail:
     trace_qcow2_l2_allocate_done(bs, l1_index, ret);
-    qcow2_cache_put(bs, s->l2_table_cache, (void**) table);
+    if (l2_table != NULL) {
+        qcow2_cache_put(bs, s->l2_table_cache, (void**) table);
+    }
     s->l1_table[l1_index] = old_l2_offset;
     return ret;
 }