[PATCH 4.14 008/167] IB/core: Avoid a potential OOPs for an unused optional parameter

Greg Kroah-Hartman
2018-02-21T12:46:59Z

From: Michael J. Ruhl <michael.j.ruhl@intel.com>

commit 2ff124d597c2df8696169ce0006fc974c49a4569 upstream.

The ev_file is an optional parameter for CQ creation. If the parameter
is not passed, the ev_file pointer will be NULL. Using that pointer
to set the cq_context will result in an OOPs.

Verify that ev_file is not NULL before using.

Cc: <stable@vger.kernel.org> # 4.14.x
Fixes: 9ee79fce3642 ("IB/core: Add completion queue (cq) object actions")
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/infiniband/core/uverbs_std_types.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/infiniband/core/uverbs_std_types.c
+++ b/drivers/infiniband/core/uverbs_std_types.c
@@ -315,7 +315,7 @@ static int uverbs_create_cq_handler(stru
cq->uobject = &obj->uobject;
cq->comp_handler = ib_uverbs_comp_handler;
cq->event_handler = ib_uverbs_cq_event_handler;
- cq->cq_context = &ev_file->ev_queue;
+ cq->cq_context = ev_file ? &ev_file->ev_queue : NULL;
obj->uobject.object = cq;
obj->uobject.user_handle = user_handle;
atomic_set(&cq->usecnt, 0);