[PATCH 4.17 008/324] IB/mlx4: Fix an error handling path in mlx4_ib_rereg_user_mr()

[Greg Kroah-Hartman]

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

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

From: Christophe Jaillet <christophe.jaillet@xxxxxxxxxx>

[ Upstream commit 3dc7c7badb7502ec3e3aa817a8bdd9e53aa54c52 ]

Before returning -EPERM we should release some resources, as already done
in the other error handling path of the function.

Fixes: d8f9cc328c88 ("IB/mlx4: Mark user MR as writable if actual virtual memory is writable")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/infiniband/hw/mlx4/mr.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/infiniband/hw/mlx4/mr.c
+++ b/drivers/infiniband/hw/mlx4/mr.c
@@ -486,8 +486,11 @@ int mlx4_ib_rereg_user_mr(struct ib_mr *
 	}
 
 	if (flags & IB_MR_REREG_ACCESS) {
-		if (ib_access_writable(mr_access_flags) && !mmr->umem->writable)
-			return -EPERM;
+		if (ib_access_writable(mr_access_flags) &&
+		    !mmr->umem->writable) {
+			err = -EPERM;
+			goto release_mpt_entry;
+		}
 
 		err = mlx4_mr_hw_change_access(dev->dev, *pmpt_entry,
 					       convert_access(mr_access_flags));