From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Borkmann , John Fastabend , Song Liu , Sasha Levin Subject: [PATCH 4.18 182/228] bpf, sockmap: fix sock_hash_alloc and reject zero-sized keys Date: Tue, 2 Oct 2018 06:24:39 -0700 Message-Id: <20181002132510.714283699@linuxfoundation.org> In-Reply-To: <20181002132459.032960735@linuxfoundation.org> References: <20181002132459.032960735@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Borkmann [ Upstream commit b845c898b2f1ea458d5453f0fa1da6e2dfce3bb4 ] Currently, it is possible to create a sock hash map with key size of 0 and have the kernel return a fd back to user space. This is invalid for hash maps (and kernel also hasn't been tested for zero key size support in general at this point). Thus, reject such configuration. Fixes: 81110384441a ("bpf: sockmap, add hash map support") Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Acked-by: Song Liu Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/sockmap.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/kernel/bpf/sockmap.c +++ b/kernel/bpf/sockmap.c @@ -2143,7 +2143,9 @@ static struct bpf_map *sock_hash_alloc(u return ERR_PTR(-EPERM); /* check sanity of attributes */ - if (attr->max_entries == 0 || attr->value_size != 4 || + if (attr->max_entries == 0 || + attr->key_size == 0 || + attr->value_size != 4 || attr->map_flags & ~SOCK_CREATE_FLAG_MASK) return ERR_PTR(-EINVAL);