From patchwork Wed Oct 9 16:09:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 1173844 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ubuntu.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46pK0c3jb2z9s7T for ; Thu, 10 Oct 2019 03:09:20 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731748AbfJIQJS (ORCPT ); Wed, 9 Oct 2019 12:09:18 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:41923 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731452AbfJIQJR (ORCPT ); Wed, 9 Oct 2019 12:09:17 -0400 Received: from [213.220.153.21] (helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1iIEWX-00034Q-5J; Wed, 09 Oct 2019 16:09:13 +0000 From: Christian Brauner To: Alexei Starovoitov , Daniel Borkmann , bpf@vger.kernel.org Cc: Martin KaFai Lau , Song Liu , Yonghong Song , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Christian Brauner Subject: [PATCH 1/3] bpf: use check_zeroed_user() in bpf_check_uarg_tail_zero() Date: Wed, 9 Oct 2019 18:09:05 +0200 Message-Id: <20191009160907.10981-2-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191009160907.10981-1-christian.brauner@ubuntu.com> References: <20191009160907.10981-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org In v5.4-rc2 we added a new helper (cf. [1]) check_zeroed_user() which does what bpf_check_uarg_tail_zero() is doing generically. We're slowly switching such codepaths over to use check_zeroed_user() instead of using their own hand-rolled version. [1]: f5a1a536fa14 ("lib: introduce copy_struct_from_user() helper") Signed-off-by: Christian Brauner Acked-by: Aleksa Sarai --- kernel/bpf/syscall.c | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 82eabd4e38ad..78790778f101 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -63,30 +63,22 @@ int bpf_check_uarg_tail_zero(void __user *uaddr, size_t expected_size, size_t actual_size) { - unsigned char __user *addr; - unsigned char __user *end; - unsigned char val; + size_t size = min(expected_size, actual_size); + size_t rest = max(expected_size, actual_size) - size; int err; if (unlikely(actual_size > PAGE_SIZE)) /* silly large */ return -E2BIG; - if (unlikely(!access_ok(uaddr, actual_size))) - return -EFAULT; - if (actual_size <= expected_size) return 0; - addr = uaddr + expected_size; - end = uaddr + actual_size; + err = check_zeroed_user(uaddr + expected_size, rest); + if (err < 0) + return err; - for (; addr < end; addr++) { - err = get_user(val, addr); - if (err) - return err; - if (val) - return -E2BIG; - } + if (err) + return -E2BIG; return 0; } From patchwork Wed Oct 9 16:09:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 1173848 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ubuntu.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46pK0q23rmz9sDQ for ; Thu, 10 Oct 2019 03:09:31 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731714AbfJIQJQ (ORCPT ); Wed, 9 Oct 2019 12:09:16 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:41921 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731226AbfJIQJQ (ORCPT ); Wed, 9 Oct 2019 12:09:16 -0400 Received: from [213.220.153.21] (helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1iIEWX-00034Q-Hp; Wed, 09 Oct 2019 16:09:13 +0000 From: Christian Brauner To: Alexei Starovoitov , Daniel Borkmann , bpf@vger.kernel.org Cc: Martin KaFai Lau , Song Liu , Yonghong Song , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Christian Brauner Subject: [PATCH 2/3] bpf: use copy_struct_from_user() in bpf_prog_get_info_by_fd() Date: Wed, 9 Oct 2019 18:09:06 +0200 Message-Id: <20191009160907.10981-3-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191009160907.10981-1-christian.brauner@ubuntu.com> References: <20191009160907.10981-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org In v5.4-rc2 we added a new helper (cf. [1]) copy_struct_from_user(). This helper is intended for all codepaths that copy structs from userspace that are versioned by size. bpf_prog_get_info_by_fd() does exactly what copy_struct_from_user() is doing. Note that copy_struct_from_user() is calling min() already. So technically, the min_t() call could go. But the info_len is used further below so leave it. [1]: f5a1a536fa14 ("lib: introduce copy_struct_from_user() helper") Signed-off-by: Christian Brauner Acked-by: Aleksa Sarai --- kernel/bpf/syscall.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 78790778f101..6f4f9097b1fe 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2312,13 +2312,10 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, u32 ulen; int err; - err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len); + info_len = min_t(u32, sizeof(info), info_len); + err = copy_struct_from_user(&info, sizeof(info), uinfo, info_len); if (err) return err; - info_len = min_t(u32, sizeof(info), info_len); - - if (copy_from_user(&info, uinfo, info_len)) - return -EFAULT; info.type = prog->type; info.id = prog->aux->id; From patchwork Wed Oct 9 16:09:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 1173849 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ubuntu.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46pK0s28vfz9s7T for ; Thu, 10 Oct 2019 03:09:33 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731786AbfJIQJc (ORCPT ); Wed, 9 Oct 2019 12:09:32 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:41924 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731686AbfJIQJQ (ORCPT ); Wed, 9 Oct 2019 12:09:16 -0400 Received: from [213.220.153.21] (helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1iIEWX-00034Q-U1; Wed, 09 Oct 2019 16:09:13 +0000 From: Christian Brauner To: Alexei Starovoitov , Daniel Borkmann , bpf@vger.kernel.org Cc: Martin KaFai Lau , Song Liu , Yonghong Song , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Christian Brauner Subject: [PATCH 3/3] bpf: use copy_struct_from_user() in bpf() syscall Date: Wed, 9 Oct 2019 18:09:07 +0200 Message-Id: <20191009160907.10981-4-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191009160907.10981-1-christian.brauner@ubuntu.com> References: <20191009160907.10981-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org In v5.4-rc2 we added a new helper (cf. [1]) copy_struct_from_user(). This helper is intended for all codepaths that copy structs from userspace that are versioned by size. The bpf() syscall does exactly what copy_struct_from_user() is doing. Note that copy_struct_from_user() is calling min() already. So technically, the min_t() call could go. But the size is used further below so leave it. [1]: f5a1a536fa14 ("lib: introduce copy_struct_from_user() helper") Signed-off-by: Christian Brauner Acked-by: Aleksa Sarai --- kernel/bpf/syscall.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 6f4f9097b1fe..6fdcbdb27501 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2819,14 +2819,11 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN)) return -EPERM; - err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); - if (err) - return err; size = min_t(u32, size, sizeof(attr)); - /* copy attributes from user space, may be less than sizeof(bpf_attr) */ - if (copy_from_user(&attr, uattr, size) != 0) - return -EFAULT; + err = copy_struct_from_user(&attr, sizeof(attr), uattr, size); + if (err) + return err; err = security_bpf(cmd, &attr, size); if (err < 0)