From patchwork Thu Jul 21 02:48:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joanne Koong X-Patchwork-Id: 12924692 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 897B5C43334 for ; Thu, 21 Jul 2022 02:49:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229680AbiGUCtc (ORCPT ); Wed, 20 Jul 2022 22:49:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229482AbiGUCtb (ORCPT ); Wed, 20 Jul 2022 22:49:31 -0400 Received: from 66-220-155-178.mail-mxout.facebook.com (66-220-155-178.mail-mxout.facebook.com [66.220.155.178]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B3AC54F1A6 for ; Wed, 20 Jul 2022 19:49:30 -0700 (PDT) Received: by devbig010.atn6.facebook.com (Postfix, from userid 115148) id F1697F3E6F95; Wed, 20 Jul 2022 19:49:17 -0700 (PDT) From: Joanne Koong To: bpf@vger.kernel.org Cc: andrii@kernel.org, daniel@iogearbox.net, ast@kernel.org, Joanne Koong Subject: [PATCH bpf-next v1 2/2] selftests/bpf: add extra test for using dynptr data slice after release Date: Wed, 20 Jul 2022 19:48:21 -0700 Message-Id: <20220721024821.251231-2-joannelkoong@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220721024821.251231-1-joannelkoong@gmail.com> References: <20220721024821.251231-1-joannelkoong@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add an additional test, "data_slice_use_after_release2", for ensuring that data slices are correctly invalidated by the verifier after the dynptr whose ref obj id they track is released. In particular, this tests data slice invalidation for dynptrs located at a non-zero offset from the frame pointer. Signed-off-by: Joanne Koong --- .../testing/selftests/bpf/prog_tests/dynptr.c | 3 +- .../testing/selftests/bpf/progs/dynptr_fail.c | 32 ++++++++++++++++++- 2 files changed, 33 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/dynptr.c b/tools/testing/selftests/bpf/prog_tests/dynptr.c index 3c7aa82b98e2..bcf80b9f7c27 100644 --- a/tools/testing/selftests/bpf/prog_tests/dynptr.c +++ b/tools/testing/selftests/bpf/prog_tests/dynptr.c @@ -22,7 +22,8 @@ static struct { {"add_dynptr_to_map2", "invalid indirect read from stack"}, {"data_slice_out_of_bounds_ringbuf", "value is outside of the allowed memory range"}, {"data_slice_out_of_bounds_map_value", "value is outside of the allowed memory range"}, - {"data_slice_use_after_release", "invalid mem access 'scalar'"}, + {"data_slice_use_after_release1", "invalid mem access 'scalar'"}, + {"data_slice_use_after_release2", "invalid mem access 'scalar'"}, {"data_slice_missing_null_check1", "invalid mem access 'mem_or_null'"}, {"data_slice_missing_null_check2", "invalid mem access 'mem_or_null'"}, {"invalid_helper1", "invalid indirect read from stack"}, diff --git a/tools/testing/selftests/bpf/progs/dynptr_fail.c b/tools/testing/selftests/bpf/progs/dynptr_fail.c index d811cff73597..d8c4ed3ee146 100644 --- a/tools/testing/selftests/bpf/progs/dynptr_fail.c +++ b/tools/testing/selftests/bpf/progs/dynptr_fail.c @@ -248,7 +248,7 @@ int data_slice_out_of_bounds_map_value(void *ctx) /* A data slice can't be used after it has been released */ SEC("?raw_tp/sys_nanosleep") -int data_slice_use_after_release(void *ctx) +int data_slice_use_after_release1(void *ctx) { struct bpf_dynptr ptr; struct sample *sample; @@ -272,6 +272,36 @@ int data_slice_use_after_release(void *ctx) return 0; } +SEC("?raw_tp/sys_nanosleep") +int data_slice_use_after_release2(void *ctx) +{ + struct bpf_dynptr ptr1, ptr2; + struct sample *sample; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr1); + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr2); + + sample = bpf_dynptr_data(&ptr2, 0, sizeof(*sample)); + if (!sample) + goto done; + + sample->pid = 23; + + bpf_ringbuf_submit_dynptr(&ptr2, 0); + + /* this should fail */ + sample->pid = 23; + + bpf_ringbuf_submit_dynptr(&ptr1, 0); + + return 0; + +done: + bpf_ringbuf_discard_dynptr(&ptr2, 0); + bpf_ringbuf_discard_dynptr(&ptr1, 0); + return 0; +} + /* A data slice must be first checked for NULL */ SEC("?raw_tp/sys_nanosleep") int data_slice_missing_null_check1(void *ctx)