From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52864) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aR70q-0003Zv-P6 for qemu-devel@nongnu.org; Wed, 03 Feb 2016 18:39:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aR70p-0006s4-V3 for qemu-devel@nongnu.org; Wed, 03 Feb 2016 18:39:04 -0500 From: John Snow Date: Wed, 3 Feb 2016 18:38:57 -0500 Message-Id: <1454542737-14742-1-git-send-email-jsnow@redhat.com> Subject: [Qemu-devel] [PATCH] qemu-img: initialize MapEntry object List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, John Snow , famz@redhat.com, qemu-devel@nongnu.org Commit 16b0d555 introduced an issue where we are not initializing has_filename for the 'next' MapEntry object, which leads to interesting errors in Valgrind and Clang -fsanitize=undefined both. Zero the stack object at allocation AND make sure the utility to populate the fields properly marks has_filename as false if applicable. Signed-off-by: John Snow --- qemu-img.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/qemu-img.c b/qemu-img.c index f121980..5a85178 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -2231,6 +2231,9 @@ static int get_block_status(BlockDriverState *bs, int64_t sector_num, if (file && e->has_offset) { e->has_filename = true; e->filename = file->filename; + } else { + e->has_filename = false; + e->filename = NULL; } return 0; } @@ -2264,7 +2267,7 @@ static int img_map(int argc, char **argv) BlockDriverState *bs; const char *filename, *fmt, *output; int64_t length; - MapEntry curr = { .length = 0 }, next; + MapEntry curr = { .length = 0 }, next = { .length = 0 }; int ret = 0; fmt = NULL; -- 2.4.3