From: Roman Gushchin <guro@fb.com>
Date: Fri, 28 Sep 2018 14:33:21 +0100
Subject: bpf: harden flags check in cgroup_storage_update_elem()
Patch-mainline: v4.19-rc7
Git-commit: 4288ea006c73e37c2a4f60dfaef20dd167b8df31
References: bsc#1109837
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 <guro@fb.com>
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
kernel/bpf/local_storage.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/bpf/local_storage.c
+++ b/kernel/bpf/local_storage.c
@@ -129,7 +129,7 @@ static int cgroup_storage_update_elem(st
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,