From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 2 Jun 2021 18:48:21 +0000 (-0400)
Subject: iov_iter_fault_in_readable() should do nothing in xarray case
X-Git-Tag: v5.4.132~331
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=63e68b5636495459704b7e7812fffd9f4a8dca8c;p=users%2Fdwmw2%2Flinux.git

iov_iter_fault_in_readable() should do nothing in xarray case

commit 0e8f0d67401589a141950856902c7d0ec8d9c985 upstream.

... and actually should just check it's given an iovec-backed iterator
in the first place.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 9450e19657594..41b06af195368 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -422,7 +422,7 @@ int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
 	int err;
 	struct iovec v;
 
-	if (!(i->type & (ITER_BVEC|ITER_KVEC))) {
+	if (iter_is_iovec(i)) {
 		iterate_iovec(i, bytes, v, iov, skip, ({
 			err = fault_in_pages_readable(v.iov_base, v.iov_len);
 			if (unlikely(err))