From b0584ea66d73919cbf5878a3420a837f06ab8396 Mon Sep 17 00:00:00 2001 From: Roman Gushchin Date: Tue, 2 Oct 2018 02:41:53 +0000 Subject: [PATCH] bpf: don't accept cgroup local storage with zero value size Explicitly forbid creating cgroup local storage maps with zero value size, as it makes no sense and might even cause a panic. Reported-by: syzbot+18628320d3b14a5c459c@syzkaller.appspotmail.com Signed-off-by: Roman Gushchin Cc: Alexei Starovoitov Cc: Daniel Borkmann Signed-off-by: Daniel Borkmann --- kernel/bpf/local_storage.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c index 94126cbffc88..830d7f095748 100644 --- a/kernel/bpf/local_storage.c +++ b/kernel/bpf/local_storage.c @@ -195,6 +195,9 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr) if (attr->key_size != sizeof(struct bpf_cgroup_storage_key)) return ERR_PTR(-EINVAL); + if (attr->value_size == 0) + return ERR_PTR(-EINVAL); + if (attr->value_size > PAGE_SIZE) return ERR_PTR(-E2BIG);