From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lorenz Bauer Subject: [PATCH v2 0/4] Fix unsafe BPF_PROG_TEST_RUN interface Date: Tue, 20 Nov 2018 15:43:02 +0000 Message-ID: <20181120154306.16657-1-lmb@cloudflare.com> References: <20181116125329.3974-1-lmb@cloudflare.com> Return-path: In-Reply-To: <20181116125329.3974-1-lmb@cloudflare.com> Sender: netdev-owner@vger.kernel.org To: ast@kernel.org, daniel@iogearbox.net Cc: netdev@vger.kernel.org, linux-api@vger.kernel.org, ys114321@gmail.com, Lorenz Bauer List-Id: linux-api@vger.kernel.org Right now, there is no safe way to use BPF_PROG_TEST_RUN with data_out. This is because bpf_test_finish copies the output buffer to user space without checking its size. This can lead to the kernel overwriting data in user space after the buffer if xdp_adjust_head and friends are in play. Changes in v2: * Make the syscall return ENOSPC if data_size_out is too small * Make bpf_prog_test_run return EINVAL if size_out is missing * Document the new behaviour of data_size_out Lorenz Bauer (4): bpf: respect size hint to BPF_PROG_TEST_RUN if present tools: sync uapi/linux/bpf.h libbpf: require size hint in bpf_prog_test_run selftests: add a test for bpf_prog_test_run output size include/uapi/linux/bpf.h | 7 ++-- net/bpf/test_run.c | 15 ++++++-- tools/include/uapi/linux/bpf.h | 7 ++-- tools/lib/bpf/bpf.c | 7 +++- tools/testing/selftests/bpf/test_progs.c | 44 ++++++++++++++++++++++++ 5 files changed, 73 insertions(+), 7 deletions(-) -- 2.17.1