From: Leon Romanovsky <leonro@mellanox.com>
Date: Tue, 13 Mar 2018 13:29:24 +0000 (+0200)
Subject: RDMA/mlx5: Protect from NULL pointer derefence
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=28ce82e3c8b116f09ea539e15bbb9f0f09f5fa32;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

RDMA/mlx5: Protect from NULL pointer derefence

commit 4289861d88d6c7b5e4c8cc7fe2ad6cdf0cdfc366 upstream.

The mlx5_ib_alloc_implicit_mr() can fail to acquire pages
and the returned mr pointer won't be valid. Ensure that it
is not error prior to access.

Cc: <stable@vger.kernel.org> # 4.10
Fixes: 81713d3788d2 ("IB/mlx5: Add implicit MR support")
Reported-by: Noa Osherovich <noaos@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index 6d48d8a93b62..538f1784863a 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -1220,6 +1220,8 @@ struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 			return ERR_PTR(-EINVAL);
 
 		mr = mlx5_ib_alloc_implicit_mr(to_mpd(pd), access_flags);
+		if (IS_ERR(mr))
+			return ERR_CAST(mr);
 		return &mr->ibmr;
 	}
 #endif