[PATCH 3.16 045/294] IB/cxgb3: Fix error codes in iwch_alloc_mr()

[Ben Hutchings]

3.16.50-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit 9064d6055c14f700aa13f7c72fd3e63d12bee643 upstream.

We accidentally don't set the error code on some error paths.  It means
return ERR_PTR(0) which is NULL and results in a NULL dereference in the
caller.

Fixes: 13a239330abd ("RDMA/cxgb3: Don't ignore insert_handle() failures")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Acked-by: Steve Wise <swise@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
[bwh: Backported to 3.16: drop inapplicable hunk]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/drivers/infiniband/hw/cxgb3/iwch_provider.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_provider.c
@@ -794,7 +794,7 @@ static struct ib_mr *iwch_alloc_fast_reg
 	struct iwch_mr *mhp;
 	u32 mmid;
 	u32 stag = 0;
-	int ret = 0;
+	int ret = -ENOMEM;
 
 	php = to_iwch_pd(pd);
 	rhp = php->rhp;
@@ -817,7 +817,8 @@ static struct ib_mr *iwch_alloc_fast_reg
 	mhp->attr.state = 1;
 	mmid = (stag) >> 8;
 	mhp->ibmr.rkey = mhp->ibmr.lkey = stag;
-	if (insert_handle(rhp, &rhp->mmidr, mhp, mmid))
+	ret = insert_handle(rhp, &rhp->mmidr, mhp, mmid);
+	if (ret)
 		goto err3;
 
 	PDBG("%s mmid 0x%x mhp %p stag 0x%x\n", __func__, mmid, mhp, stag);