From: Christoph Hellwig <hch@lst.de>
Date: Mon, 11 Jan 2021 17:19:26 +0000 (+0100)
Subject: iov_iter: fix the uaccess area in copy_compat_iovec_from_user
X-Git-Tag: v5.10.17~622
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=37d4f78ae274d11c26eb7deb912f8fdf12bd2283;p=platform%2Fkernel%2Flinux-rpi.git

iov_iter: fix the uaccess area in copy_compat_iovec_from_user

[ Upstream commit a959a9782fa87669feeed095ced5d78181a7c02d ]

sizeof needs to be called on the compat pointer, not the native one.

Fixes: 89cd35c58bc2 ("iov_iter: transparently handle compat iovecs in import_iovec")
Reported-by: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 1635111..a21e6a5 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1658,7 +1658,7 @@ static int copy_compat_iovec_from_user(struct iovec *iov,
 		(const struct compat_iovec __user *)uvec;
 	int ret = -EFAULT, i;
 
-	if (!user_access_begin(uvec, nr_segs * sizeof(*uvec)))
+	if (!user_access_begin(uiov, nr_segs * sizeof(*uiov)))
 		return -EFAULT;
 
 	for (i = 0; i < nr_segs; i++) {