[PATCH 4.4 52/97] RDMA/ucma: Dont allow setting RDMA_OPTION_IB_PATH without an RDMA device

From: Greg Kroah-Hartman
Date: Sun Apr 22 2018 - 10:42:36 EST

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


From: Roland Dreier <roland@xxxxxxxxxxxxxxx>

commit 8435168d50e66fa5eae01852769d20a36f9e5e83 upstream.

Check to make sure that ctx->cm_id->device is set before we use it.
Otherwise userspace can trigger a NULL dereference by doing
RDMA_USER_CM_CMD_SET_OPTION on an ID that is not bound to a device.

Cc: <stable@xxxxxxxxxxxxxxx>
Reported-by: <syzbot+a67bc93e14682d92fc2f@xxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Roland Dreier <roland@xxxxxxxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/infiniband/core/ucma.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -1230,6 +1230,9 @@ static int ucma_set_ib_path(struct ucma_
if (!optlen)
return -EINVAL;

+ if (!ctx->cm_id->device)
+ return -EINVAL;
memset(&sa_path, 0, sizeof(sa_path));

ib_sa_unpack_path(path_data->path_rec, &sa_path);