Commit 20c7840a authored Apr 09, 2017 by Michael J. Ruhl Committed by Doug Ledford Apr 28, 2017

IB/core: If the MGID/MLID pair is not on the list return an error



A list of MGID/MLID pairs is built when doing a multicast attach.  When
the multicast detach is called, the list is searched, and regardless of
the search outcome, the driver detach is called.

If an MGID/MLID pair is not on the list, driver detach should not be
called, and an error should be returned.  Calling the driver without
removing an MGID/MLID pair from the list can leave the core and driver
out of sync.

Fixes: f4e40156 ("IB/uverbs: track multicast group membership for userspace QPs")
Cc: stable@vger.kernel.org
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

parent 2443c6cc

drivers/infiniband/core/uverbs_cmd.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -2658,6 +2658,7 @@ ssize_t ib_uverbs_detach_mcast(struct ib_uverbs_file *file,
		struct ib_qp *qp;
		struct ib_uverbs_mcast_entry *mcast;
		int ret = -EINVAL;
		bool found = false;

		if (copy_from_user(&cmd, buf, sizeof cmd))
		return -EFAULT;
		@@ -2669,18 +2670,22 @@ ssize_t ib_uverbs_detach_mcast(struct ib_uverbs_file *file,
		obj = container_of(qp->uobject, struct ib_uqp_object, uevent.uobject);
		mutex_lock(&obj->mcast_lock);

		ret = ib_detach_mcast(qp, (union ib_gid *) cmd.gid, cmd.mlid);
		if (ret)
		goto out_put;

		list_for_each_entry(mcast, &obj->mcast_list, list)
		if (cmd.mlid == mcast->lid &&
		!memcmp(cmd.gid, mcast->gid.raw, sizeof mcast->gid.raw)) {
		list_del(&mcast->list);
		kfree(mcast);
		found = true;
		break;
		}

		if (!found) {
		ret = -EINVAL;
		goto out_put;
		}

		ret = ib_detach_mcast(qp, (union ib_gid *)cmd.gid, cmd.mlid);

		out_put:
		mutex_unlock(&obj->mcast_lock);
		uobj_put_obj_read(qp);