IB/uverbs: Release event file reference on ib_uverbs_create_cq() error

ib_uverbs_create_cq() should release the completion channel event file
if an error occurs after it looks it up.  Also, if userspace asks for
a completion channel and we don't find it, an error should be returned
instead of silently creating a CQ without a completion channel.

Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 12d6cc0..a02c5a0 100644 (file)
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -594,13 +594,18 @@ ssize_t ib_uverbs_create_cq(struct ib_uverbs_file *file,
        if (cmd.comp_vector >= file->device->num_comp_vectors)
                return -EINVAL;
 
-       if (cmd.comp_channel >= 0)
-               ev_file = ib_uverbs_lookup_comp_file(cmd.comp_channel);
-
        uobj = kmalloc(sizeof *uobj, GFP_KERNEL);
        if (!uobj)
                return -ENOMEM;
 
+       if (cmd.comp_channel >= 0) {
+               ev_file = ib_uverbs_lookup_comp_file(cmd.comp_channel);
+               if (!ev_file) {
+                       ret = -EINVAL;
+                       goto err;
+               }
+       }
+
        uobj->uobject.user_handle   = cmd.user_handle;
        uobj->uobject.context       = file->ucontext;
        uobj->uverbs_file           = file;
@@ -664,6 +669,8 @@ err_up:
        ib_destroy_cq(cq);
 
 err:
+       if (ev_file)
+               ib_uverbs_release_ucq(file, ev_file, uobj);
        kfree(uobj);
        return ret;
 }