From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AE877199 for ; Tue, 21 Nov 2023 17:17:07 -0800 (PST) Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3ALNMW0h030143 for ; Tue, 21 Nov 2023 17:17:07 -0800 Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3uh65qrpnr-4 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 21 Nov 2023 17:17:07 -0800 Received: from twshared40933.03.prn6.facebook.com (2620:10d:c0a8:1c::1b) by mail.thefacebook.com (2620:10d:c0a8:82::b) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.34; Tue, 21 Nov 2023 17:17:04 -0800 Received: by devbig019.vll3.facebook.com (Postfix, from userid 137359) id 456C13BE884F1; Tue, 21 Nov 2023 17:16:59 -0800 (PST) From: Andrii Nakryiko To: , , , CC: , Subject: [PATCH bpf-next 00/10] BPF verifier retval logic fixes Date: Tue, 21 Nov 2023 17:16:46 -0800 Message-ID: <20231122011656.1105943-1-andrii@kernel.org> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-ORIG-GUID: jZm34nrEp4L3TdVMn6VmVUX4slAmce03 X-Proofpoint-GUID: jZm34nrEp4L3TdVMn6VmVUX4slAmce03 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.987,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-11-21_16,2023-11-21_01,2023-05-22_02 This patch set fixes BPF verifier logic around validating and enforcing r= eturn values for BPF programs that have specific range of expected return value= s. Both sync and async callbacks have similar logic and are fixes as well. A few tests are added that would fail without the fixes in this patch set= . Also, while at it, we extend retval checking logic to use not just tnum v= alue, but also umin/umax range, avoiding future potential issues if expected ra= nge cannot be represented precisely by tnum (e.g., [0, 2] is not representabl= e by tnum and is treated as [0, 3]). There is a little bit of refactoring to unify async callback and program = exit logic to avoid duplication of checks as much as possible. Andrii Nakryiko (10): bpf: rearrange bpf_func_state fields to save a bit of memory bpf: provide correct register name for exception callback retval check bpf: enforce precision of R0 on callback return bpf: enforce exact retval range on subprog/callback exit selftests/bpf: add selftest validating callback result is enforced bpf: enforce precise retval range on program exit bpf: unify async callback and program retval checks bpf: enforce precision of R0 on program/async callback return selftests/bpf: validate async callback return value check correctness selftests/bpf: adjust global_func15 test to validate prog exit precision include/linux/bpf_verifier.h | 9 +- kernel/bpf/verifier.c | 133 +++++++++++------- .../selftests/bpf/progs/exceptions_assert.c | 2 +- .../selftests/bpf/progs/exceptions_fail.c | 2 +- .../selftests/bpf/progs/test_global_func15.c | 31 +++- .../selftests/bpf/progs/timer_failure.c | 31 ++-- .../selftests/bpf/progs/user_ringbuf_fail.c | 2 +- .../bpf/progs/verifier_cgroup_inv_retcode.c | 8 +- .../bpf/progs/verifier_netfilter_retcode.c | 2 +- .../bpf/progs/verifier_subprog_precision.c | 45 ++++++ 10 files changed, 198 insertions(+), 67 deletions(-) --=20 2.34.1