Commit 7392ed17 authored by Al Viro's avatar Al Viro
Browse files

iov_iter_get_pages{,_alloc}(): cap the maxsize with MAX_RW_COUNT 



All callers can and should handle iov_iter_get_pages() returning
fewer pages than requested.  All in-kernel ones do.  And it makes
the arithmetical overflow analysis much simpler...

Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 18fa9af7

lib/iov_iter.c

+4 −0
Original line number Diff line number Diff line
@@ -1348,6 +1348,8 @@ ssize_t iov_iter_get_pages(struct iov_iter *i, 
		maxsize = i->count;

	if (!maxsize)

		return 0;

	if (maxsize > MAX_RW_COUNT)

		maxsize = MAX_RW_COUNT;



	if (likely(iter_is_iovec(i))) {

		unsigned int gup_flags = 0;
@@ -1474,6 +1476,8 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 
		maxsize = i->count;

	if (!maxsize)

		return 0;

	if (maxsize > MAX_RW_COUNT)

		maxsize = MAX_RW_COUNT;



	if (likely(iter_is_iovec(i))) {

		unsigned int gup_flags = 0;