[PATCH 5.10 097/199] iov_iter: fix the uaccess area in copy_compat_iovec_from_user

[Greg Kroah-Hartman]

From: Christoph Hellwig <hch@xxxxxx>

[ 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@xxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 lib/iov_iter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 1635111c5bd2a..a21e6a5792c5a 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++) {
-- 
2.27.0