Commit b0584ea6 authored Oct 02, 2018 by Roman Gushchin Committed by Daniel Borkmann Oct 02, 2018

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 <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

parent 4288ea00

kernel/bpf/local_storage.c

+3 −0

Original line number	Original line	Diff line number	Diff line
	@@ -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))		if (attr->key_size != sizeof(struct bpf_cgroup_storage_key))
	return ERR_PTR(-EINVAL);		return ERR_PTR(-EINVAL);

			if (attr->value_size == 0)
			return ERR_PTR(-EINVAL);

	if (attr->value_size > PAGE_SIZE)		if (attr->value_size > PAGE_SIZE)
	return ERR_PTR(-E2BIG);		return ERR_PTR(-E2BIG);