[PATCH] CA-392151: fix nfs gup uninitialized iov_offset defect

[Chunjie Zhu]

  nfs aio code path, iov_offset is not initialized before used

  nfs aio function call graph,
    io_submit
    aio_read
    aio_setup_rw
    import_single_range
    iov_iter_ubuf           # do not initialize iov_offset
    call_read_iter
    nfs_file_read
    nfs_file_direct_read
    nfs_direct_read_schedule_iovec
    iov_iter_get_pages_alloc2
    __iov_iter_get_pages_alloc
    first_iovec_segment     # iov_offset is used, not initialized

Signed-off-by: Chunjie Zhu <chunjie.zhu@xxxxxxxxx>
---
 include/linux/uio.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/uio.h b/include/linux/uio.h
index 42bce38a8e87..2121424204c2 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -386,6 +386,7 @@ static inline void iov_iter_ubuf(struct iov_iter *i, unsigned int direction,
 		.user_backed = true,
 		.data_source = direction,
 		.ubuf = buf,
+		.iov_offset = 0,
 		.count = count,
 		.nr_segs = 1
 	};
-- 
2.34.1