[PATCH] bpf: drop refcount if bpf_map_new_fd() fails in map_create()

[zerons]

In bpf/syscall.c, map_create() first set map->usercnt to 1, a file descriptor is
supposed to return to userspace. When bpf_map_new_fd() fails, drop the refcount.

Signed-off-by: Peng Sun <sironhide0n...@gmail.com>
---
 kernel/bpf/syscall.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index cf5040f..1c4f1c4 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -558,12 +558,12 @@ static int map_create(union bpf_attr *attr)
        err = bpf_map_new_fd(map, f_flags);
        if (err < 0) {
                /* failed to allocate fd.
-                * bpf_map_put() is needed because the above
+                * bpf_map_put_with_uref() is needed because the above
                 * bpf_map_alloc_id() has published the map
                 * to the userspace and the userspace may
                 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
                 */
-               bpf_map_put(map);
+               bpf_map_put_with_uref(map);
                return err;
        }

--
2.7.4