[PATCH 5.16 0620/1017] RDMA/nldev: Prevent underflow in nldev_stat_set_counter_dynamic_doit()

[Greg Kroah-Hartman]

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

[ Upstream commit 87e0eacb176f9500c2063d140c0a1d7fa51ab8a5 ]

This code checks "index" for an upper bound but it does not check for
negatives.  Change the type to unsigned to prevent underflows.

Fixes: 3c3c1f141639 ("RDMA/nldev: Allow optional-counter status configuration through RDMA netlink")
Link: https://lore.kernel.org/r/20220316083948.GC30941@kili
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/infiniband/core/nldev.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index f5aacaf7fb8e..ca24ce34da76 100644
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -1951,9 +1951,10 @@ static int nldev_stat_set_counter_dynamic_doit(struct nlattr *tb[],
 					       u32 port)
 {
 	struct rdma_hw_stats *stats;
-	int rem, i, index, ret = 0;
 	struct nlattr *entry_attr;
 	unsigned long *target;
+	int rem, i, ret = 0;
+	u32 index;
 
 	stats = ib_get_hw_stats_port(device, port);
 	if (!stats)
-- 
2.34.1