On Wed, 02/03 18:38, John Snow wrote:
> 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 <js...@redhat.com>
> ---
> 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
>
Reviewed-by: Fam Zheng <f...@redhat.com>
