4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit 07d432bb97f19dd5e784175152f9fce3b2646133 ]

The driver may sleep under a spin lock, and the function call path is:
post_one_send (acquire the lock by spin_lock_irqsave)
  init_send_wqe
    copy_from_user --> may sleep

There is no flow that makes "qp->is_user" true, and copy_from_user may
cause bug when a non-user pointer is used. So the lines of copy_from_user
and check of "qp->is_user" are removed.

Signed-off-by: Jia-Ju Bai <baijiaju1...@163.com>
Reviewed-by: Leon Romanovsky <leo...@mellanox.com>
Acked-by: Moni Shoua <mo...@mellanox.com>
Signed-off-by: Doug Ledford <dledf...@redhat.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/infiniband/sw/rxe/rxe_verbs.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c 
b/drivers/infiniband/sw/rxe/rxe_verbs.c
index ced416f5dffb..ef13082d6ca1 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -729,13 +729,8 @@ static int init_send_wqe(struct rxe_qp *qp, struct 
ib_send_wr *ibwr,
 
                sge = ibwr->sg_list;
                for (i = 0; i < num_sge; i++, sge++) {
-                       if (qp->is_user && copy_from_user(p, (__user void *)
-                                           (uintptr_t)sge->addr, sge->length))
-                               return -EFAULT;
-
-                       else if (!qp->is_user)
-                               memcpy(p, (void *)(uintptr_t)sge->addr,
-                                      sge->length);
+                       memcpy(p, (void *)(uintptr_t)sge->addr,
+                                       sge->length);
 
                        p += sge->length;
                }
-- 
2.17.1



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