| Message ID | 20241031110224.293343-1-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | lib/iov_iter.c: initialize bi.bi_idx before iterating over bvec | expand |
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@lst.de> > Reported-and-tested-by: Klara Modin <klarasmodin@gmail.com> > Fixes: e4e535bff2bc ("iov_iter: don't require contiguous pages in iov_iter_extract_bvec_pages") > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > 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@lst.de>
On 10/31/24 5:02 AM, Ming Lei wrote: > Initialize bi.bi_idx as 0 before iterating over bvec, otherwise > garbage data can be used as ->bi_idx. For some reason this wasn't on lore, so manual reply to say that I applied it.
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; bi.bi_size = maxsize + skip; bi.bi_bvec_done = skip;
Initialize bi.bi_idx as 0 before iterating over bvec, otherwise garbage data can be used as ->bi_idx. Cc: Christoph Hellwig <hch@lst.de> Reported-and-tested-by: Klara Modin <klarasmodin@gmail.com> Fixes: e4e535bff2bc ("iov_iter: don't require contiguous pages in iov_iter_extract_bvec_pages") Signed-off-by: Ming Lei <ming.lei@redhat.com> --- lib/iov_iter.c | 1 + 1 file changed, 1 insertion(+)