[PATCH 4.18 032/228] IB/core: type promotion bug in rdma_rw_init_one_mr()

[Greg Kroah-Hartman]

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

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

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

[ Upstream commit c2d7c8ff89b22ddefb1ac2986c0d48444a667689 ]

"nents" is an unsigned int, so if ib_map_mr_sg() returns a negative
error code then it's type promoted to a high unsigned int which is
treated as success.

Fixes: a060b5629ab0 ("IB/core: generic RDMA READ/WRITE API")
Signed-off-by: Dan Carpenter <dan.carpenter@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/core/rw.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/infiniband/core/rw.c
+++ b/drivers/infiniband/core/rw.c
@@ -87,7 +87,7 @@ static int rdma_rw_init_one_mr(struct ib
 	}
 
 	ret = ib_map_mr_sg(reg->mr, sg, nents, &offset, PAGE_SIZE);
-	if (ret < nents) {
+	if (ret < 0 || ret < nents) {
 		ib_mr_pool_put(qp, &qp->rdma_mrs, reg->mr);
 		return -EINVAL;
 	}