[PATCH] iov_iter: Use user_read_access_begin() instead of user_access_begin()

From: Christophe Leroy
Date: Wed Mar 10 2021 - 08:09:34 EST


copy_compat_iovec_from_user() only do unsafe_get_user(),
it only requires read access.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
lib/iov_iter.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index f66c62aa7154..76952a117b47 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1665,7 +1665,7 @@ static int copy_compat_iovec_from_user(struct iovec *iov,
(const struct compat_iovec __user *)uvec;
int ret = -EFAULT, i;

- if (!user_access_begin(uiov, nr_segs * sizeof(*uiov)))
+ if (!user_read_access_begin(uiov, nr_segs * sizeof(*uiov)))
return -EFAULT;

for (i = 0; i < nr_segs; i++) {
@@ -1686,7 +1686,7 @@ static int copy_compat_iovec_from_user(struct iovec *iov,

ret = 0;
uaccess_end:
- user_access_end();
+ user_read_access_end();
return ret;
}

--
2.25.0