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authorStefan Hajnoczi <stefanha@redhat.com>2016-09-13 09:56:27 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2016-09-13 11:00:55 +0100
commit0647d47cc184da587c76743546b6af6dfdb8f1da (patch)
tree7c2f3964fb1e4b6408cddd7deeddb2423601a9a9 /block/qcow2-cluster.c
parent7263da78045dc91cc207f350911efe4259e99b3c (diff)
downloadqemu-0647d47cc184da587c76743546b6af6dfdb8f1da.tar.gz
qcow2: avoid memcpy(dst, NULL, len)
Section "7.1.4 Use of library functions" in the C99 standard says: If an argument to a function has an invalid value (such as [...] a null pointer [...]) [...] the behavior is undefined. Additionally the "searching and sorting" functions are specified as requiring valid pointer values as described in 7.1.4. This patch fixes the following sanitizer errors: block/qcow2.c:1807:41: runtime error: null pointer passed as argument 2, which is declared to never be null block/qcow2-cluster.c:86:26: runtime error: null pointer passed as argument 2, which is declared to never be null Reported-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1473758138-19260-1-git-send-email-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/qcow2-cluster.c')
-rw-r--r--block/qcow2-cluster.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index f94183529c..9ab445dd17 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -83,7 +83,9 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
}
memset(new_l1_table, 0, align_offset(new_l1_size2, 512));
- memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
+ if (s->l1_size) {
+ memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
+ }
/* write new table (align to cluster) */
BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ALLOC_TABLE);