From: Bart Van Assche <bart.vanassche@sandisk.com>
Date: Mon, 24 Apr 2017 15:15:28 -0700
Subject: [PATCH] mlx5: Avoid that mlx5_ib_sg_to_klms() overflows the klms[]
 array
References: bnc#1060662
Patch-mainline: v4.12.4
Git-commit: 99975cd4fda52974a767aa44fe0b1a8f74950d9d

commit 99975cd4fda52974a767aa44fe0b1a8f74950d9d upstream.

ib_map_mr_sg() can pass an SG-list to .map_mr_sg() that is larger
than what fits into a single MR. .map_mr_sg() must not attempt to
map more SG-list elements than what fits into a single MR.
Hence make sure that mlx5_ib_sg_to_klms() does not write outside
the MR klms[] array.

Fixes: b005d3164713 ("mlx5: Add arbitrary sg list support")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Israel Rukshin <israelr@mellanox.com>
Acked-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/infiniband/hw/mlx5/mr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index 366433f71b58..08512d4c8e89 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -1779,7 +1779,7 @@ mlx5_ib_sg_to_klms(struct mlx5_ib_mr *mr,
 	mr->ndescs = sg_nents;
 
 	for_each_sg(sgl, sg, sg_nents, i) {
-		if (unlikely(i > mr->max_descs))
+		if (unlikely(i >= mr->max_descs))
 			break;
 		klms[i].va = cpu_to_be64(sg_dma_address(sg) + sg_offset);
 		klms[i].bcount = cpu_to_be32(sg_dma_len(sg) - sg_offset);
-- 
2.14.2