On Thu, Oct 31, 2024 at 07:02:24PM +0800, Ming Lei wrote:
> Initialize bi.bi_idx as 0 before iterating over bvec, otherwise
> garbage data can be used as ->bi_idx.
>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Reported-and-tested-by: Klara Modin <klarasmodin@xxxxxxxxx>
> Fixes: e4e535bff2bc ("iov_iter: don't require contiguous pages in iov_iter_extract_bvec_pages")
> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
> ---
> lib/iov_iter.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/lib/iov_iter.c b/lib/iov_iter.c
> index 9fc06f5fb748..c761f6db3cb4 100644
> --- a/lib/iov_iter.c
> +++ b/lib/iov_iter.c
> @@ -1699,6 +1699,7 @@ static ssize_t iov_iter_extract_bvec_pages(struct iov_iter *i,
> i->bvec++;
> skip = 0;
> }
> + bi.bi_idx = 0;
Looks good, but the more future proof variant would be to
initialize bi to zero at declaration time:
struct bvec_iter bi = { };
Either way:
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
