[PATCH 2/7] io_uring/net: simplify compat selbuf iov parsing

[Pavel Begunkov <asml.silence@gmail.com>]

Use copy_from_user() instead of open coded access_ok() + get_user(),
that's simpler and we don't care about compat that much.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/net.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/io_uring/net.c b/io_uring/net.c
index c78edfd5085e..0013a7169d10 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -215,21 +215,19 @@ static int io_compat_msg_copy_hdr(struct io_kiocb *req,
 
 	uiov = compat_ptr(msg->msg_iov);
 	if (req->flags & REQ_F_BUFFER_SELECT) {
-		compat_ssize_t clen;
-
 		if (msg->msg_iovlen == 0) {
 			sr->len = iov->iov_len = 0;
 			iov->iov_base = NULL;
 		} else if (msg->msg_iovlen > 1) {
 			return -EINVAL;
 		} else {
-			if (!access_ok(uiov, sizeof(*uiov)))
-				return -EFAULT;
-			if (__get_user(clen, &uiov->iov_len))
+			struct compat_iovec tmp_iov;
+
+			if (copy_from_user(&tmp_iov, uiov, sizeof(tmp_iov)))
 				return -EFAULT;
-			if (clen < 0)
+			if (tmp_iov.iov_len < 0)
 				return -EINVAL;
-			sr->len = clen;
+			sr->len = tmp_iov.iov_len;
 		}
 
 		return 0;
-- 
2.48.1