From 4288ea006c73e37c2a4f60dfaef20dd167b8df31 Mon Sep 17 00:00:00 2001 From: Roman Gushchin Date: Fri, 28 Sep 2018 14:33:21 +0100 Subject: [PATCH] bpf: harden flags check in cgroup_storage_update_elem() cgroup_storage_update_elem() shouldn't accept any flags argument values except BPF_ANY and BPF_EXIST to guarantee the backward compatibility, had a new flag value been added. Fixes: de9cbbaadba5 ("bpf: introduce cgroup storage maps") Signed-off-by: Roman Gushchin Reported-by: Daniel Borkmann Cc: Alexei Starovoitov Signed-off-by: Daniel Borkmann --- kernel/bpf/local_storage.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c index 22ad967..94126cb 100644 --- a/kernel/bpf/local_storage.c +++ b/kernel/bpf/local_storage.c @@ -129,7 +129,7 @@ static int cgroup_storage_update_elem(struct bpf_map *map, void *_key, struct bpf_cgroup_storage *storage; struct bpf_storage_buffer *new; - if (flags & BPF_NOEXIST) + if (flags != BPF_ANY && flags != BPF_EXIST) return -EINVAL; storage = cgroup_storage_lookup((struct bpf_cgroup_storage_map *)map, -- 2.7.4