From patchwork Wed Jun 7 23:53:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 13271492 X-Patchwork-Delegate: paul@paul-moore.com 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 3E62EC7EE25 for ; Wed, 7 Jun 2023 23:55:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232842AbjFGXzI convert rfc822-to-8bit (ORCPT ); Wed, 7 Jun 2023 19:55:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53972 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229730AbjFGXzI (ORCPT ); Wed, 7 Jun 2023 19:55:08 -0400 Received: from mx0a-00082601.pphosted.com (mx0b-00082601.pphosted.com [67.231.153.30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5374268F for ; Wed, 7 Jun 2023 16:55:03 -0700 (PDT) Received: from pps.filterd (m0089730.ppops.net [127.0.0.1]) by m0089730.ppops.net (8.17.1.19/8.17.1.19) with ESMTP id 357HCNA8003468 for ; Wed, 7 Jun 2023 16:55:03 -0700 Received: from mail.thefacebook.com ([163.114.132.120]) by m0089730.ppops.net (PPS) with ESMTPS id 3r2a82txgb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 07 Jun 2023 16:55:02 -0700 Received: from twshared44841.48.prn1.facebook.com (2620:10d:c085:108::4) by mail.thefacebook.com (2620:10d:c085:21d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Wed, 7 Jun 2023 16:54:19 -0700 Received: by devbig019.vll3.facebook.com (Postfix, from userid 137359) id BCCD432857DAC; Wed, 7 Jun 2023 16:54:06 -0700 (PDT) From: Andrii Nakryiko To: CC: , , , , , , Subject: [PATCH v2 bpf-next 06/18] bpf: centralize permissions checks for all BPF map types Date: Wed, 7 Jun 2023 16:53:40 -0700 Message-ID: <20230607235352.1723243-7-andrii@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230607235352.1723243-1-andrii@kernel.org> References: <20230607235352.1723243-1-andrii@kernel.org> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: dh6Sn1IuEIZBp1XtFj0qHcQi63H6DFof X-Proofpoint-ORIG-GUID: dh6Sn1IuEIZBp1XtFj0qHcQi63H6DFof X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.573,FMLib:17.11.176.26 definitions=2023-06-07_13,2023-06-07_01,2023-05-22_02 Precedence: bulk List-ID: This allows to do more centralized decisions later on, and generally makes it very explicit which maps are privileged and which are not (e.g., LRU_HASH and LRU_PERCPU_HASH, which are privileged HASH variants, as opposed to unprivileged HASH and HASH_PERCPU; now this is explicit and easy to verify). Signed-off-by: Andrii Nakryiko --- kernel/bpf/bloom_filter.c | 3 -- kernel/bpf/bpf_local_storage.c | 3 -- kernel/bpf/bpf_struct_ops.c | 3 -- kernel/bpf/cpumap.c | 4 -- kernel/bpf/devmap.c | 3 -- kernel/bpf/hashtab.c | 6 --- kernel/bpf/lpm_trie.c | 3 -- kernel/bpf/queue_stack_maps.c | 4 -- kernel/bpf/reuseport_array.c | 3 -- kernel/bpf/stackmap.c | 3 -- kernel/bpf/syscall.c | 47 +++++++++++++++++++ net/core/sock_map.c | 4 -- net/xdp/xskmap.c | 4 -- .../bpf/prog_tests/unpriv_bpf_disabled.c | 6 ++- 14 files changed, 52 insertions(+), 44 deletions(-) diff --git a/kernel/bpf/bloom_filter.c b/kernel/bpf/bloom_filter.c index 540331b610a9..addf3dd57b59 100644 --- a/kernel/bpf/bloom_filter.c +++ b/kernel/bpf/bloom_filter.c @@ -86,9 +86,6 @@ static struct bpf_map *bloom_map_alloc(union bpf_attr *attr) int numa_node = bpf_map_attr_numa_node(attr); struct bpf_bloom_filter *bloom; - if (!bpf_capable()) - return ERR_PTR(-EPERM); - if (attr->key_size != 0 || attr->value_size == 0 || attr->max_entries == 0 || attr->map_flags & ~BLOOM_CREATE_FLAG_MASK || diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index 47d9948d768f..b5149cfce7d4 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -723,9 +723,6 @@ int bpf_local_storage_map_alloc_check(union bpf_attr *attr) !attr->btf_key_type_id || !attr->btf_value_type_id) return -EINVAL; - if (!bpf_capable()) - return -EPERM; - if (attr->value_size > BPF_LOCAL_STORAGE_MAX_VALUE_SIZE) return -E2BIG; diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c index d3f0a4825fa6..116a0ce378ec 100644 --- a/kernel/bpf/bpf_struct_ops.c +++ b/kernel/bpf/bpf_struct_ops.c @@ -655,9 +655,6 @@ static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr) const struct btf_type *t, *vt; struct bpf_map *map; - if (!bpf_capable()) - return ERR_PTR(-EPERM); - st_ops = bpf_struct_ops_find_value(attr->btf_vmlinux_value_type_id); if (!st_ops) return ERR_PTR(-ENOTSUPP); diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index 8ec18faa74ac..8a33e8747a0e 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -28,7 +28,6 @@ #include #include #include -#include #include #include @@ -89,9 +88,6 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr) u32 value_size = attr->value_size; struct bpf_cpu_map *cmap; - if (!bpf_capable()) - return ERR_PTR(-EPERM); - /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 4 || (value_size != offsetofend(struct bpf_cpumap_val, qsize) && diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 802692fa3905..49cc0b5671c6 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -160,9 +160,6 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr) struct bpf_dtab *dtab; int err; - if (!capable(CAP_NET_ADMIN)) - return ERR_PTR(-EPERM); - dtab = bpf_map_area_alloc(sizeof(*dtab), NUMA_NO_NODE); if (!dtab) return ERR_PTR(-ENOMEM); diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 9901efee4339..56d3da7d0bc6 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -422,12 +422,6 @@ static int htab_map_alloc_check(union bpf_attr *attr) BUILD_BUG_ON(offsetof(struct htab_elem, fnode.next) != offsetof(struct htab_elem, hash_node.pprev)); - if (lru && !bpf_capable()) - /* LRU implementation is much complicated than other - * maps. Hence, limit to CAP_BPF. - */ - return -EPERM; - if (zero_seed && !capable(CAP_SYS_ADMIN)) /* Guard against local DoS, and discourage production use. */ return -EPERM; diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index e0d3ddf2037a..17c7e7782a1f 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -544,9 +544,6 @@ static struct bpf_map *trie_alloc(union bpf_attr *attr) { struct lpm_trie *trie; - if (!bpf_capable()) - return ERR_PTR(-EPERM); - /* check sanity of attributes */ if (attr->max_entries == 0 || !(attr->map_flags & BPF_F_NO_PREALLOC) || diff --git a/kernel/bpf/queue_stack_maps.c b/kernel/bpf/queue_stack_maps.c index 601609164ef3..8d2ddcb7566b 100644 --- a/kernel/bpf/queue_stack_maps.c +++ b/kernel/bpf/queue_stack_maps.c @@ -7,7 +7,6 @@ #include #include #include -#include #include #include "percpu_freelist.h" @@ -46,9 +45,6 @@ static bool queue_stack_map_is_full(struct bpf_queue_stack *qs) /* Called from syscall */ static int queue_stack_map_alloc_check(union bpf_attr *attr) { - if (!bpf_capable()) - return -EPERM; - /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 0 || attr->value_size == 0 || diff --git a/kernel/bpf/reuseport_array.c b/kernel/bpf/reuseport_array.c index cbf2d8d784b8..4b4f9670f1a9 100644 --- a/kernel/bpf/reuseport_array.c +++ b/kernel/bpf/reuseport_array.c @@ -151,9 +151,6 @@ static struct bpf_map *reuseport_array_alloc(union bpf_attr *attr) int numa_node = bpf_map_attr_numa_node(attr); struct reuseport_array *array; - if (!bpf_capable()) - return ERR_PTR(-EPERM); - /* allocate all map elements and zero-initialize them */ array = bpf_map_area_alloc(struct_size(array, ptrs, attr->max_entries), numa_node); if (!array) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index b25fce425b2c..458bb80b14d5 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -74,9 +74,6 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr) u64 cost, n_buckets; int err; - if (!bpf_capable()) - return ERR_PTR(-EPERM); - if (attr->map_flags & ~STACK_CREATE_FLAG_MASK) return ERR_PTR(-EINVAL); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 20b373dce669..093472ac40f7 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1156,6 +1156,53 @@ static int map_create(union bpf_attr *attr) if (sysctl_unprivileged_bpf_disabled && !bpf_capable()) return -EPERM; + /* check privileged map type permissions */ + switch (map_type) { + case BPF_MAP_TYPE_ARRAY: + case BPF_MAP_TYPE_PERCPU_ARRAY: + case BPF_MAP_TYPE_PROG_ARRAY: + case BPF_MAP_TYPE_PERF_EVENT_ARRAY: + case BPF_MAP_TYPE_CGROUP_ARRAY: + case BPF_MAP_TYPE_ARRAY_OF_MAPS: + case BPF_MAP_TYPE_HASH: + case BPF_MAP_TYPE_PERCPU_HASH: + case BPF_MAP_TYPE_HASH_OF_MAPS: + case BPF_MAP_TYPE_RINGBUF: + case BPF_MAP_TYPE_USER_RINGBUF: + case BPF_MAP_TYPE_CGROUP_STORAGE: + case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: + /* unprivileged */ + break; + case BPF_MAP_TYPE_SK_STORAGE: + case BPF_MAP_TYPE_INODE_STORAGE: + case BPF_MAP_TYPE_TASK_STORAGE: + case BPF_MAP_TYPE_CGRP_STORAGE: + case BPF_MAP_TYPE_BLOOM_FILTER: + case BPF_MAP_TYPE_LPM_TRIE: + case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: + case BPF_MAP_TYPE_STACK_TRACE: + case BPF_MAP_TYPE_QUEUE: + case BPF_MAP_TYPE_STACK: + case BPF_MAP_TYPE_LRU_HASH: + case BPF_MAP_TYPE_LRU_PERCPU_HASH: + case BPF_MAP_TYPE_STRUCT_OPS: + case BPF_MAP_TYPE_CPUMAP: + if (!bpf_capable()) + return -EPERM; + break; + case BPF_MAP_TYPE_SOCKMAP: + case BPF_MAP_TYPE_SOCKHASH: + case BPF_MAP_TYPE_DEVMAP: + case BPF_MAP_TYPE_DEVMAP_HASH: + case BPF_MAP_TYPE_XSKMAP: + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + break; + default: + WARN(1, "unsupported map type %d", map_type); + return -EPERM; + } + map = ops->map_alloc(attr); if (IS_ERR(map)) return PTR_ERR(map); diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 00afb66cd095..19538d628714 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -32,8 +32,6 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr) { struct bpf_stab *stab; - if (!capable(CAP_NET_ADMIN)) - return ERR_PTR(-EPERM); if (attr->max_entries == 0 || attr->key_size != 4 || (attr->value_size != sizeof(u32) && @@ -1085,8 +1083,6 @@ static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) struct bpf_shtab *htab; int i, err; - if (!capable(CAP_NET_ADMIN)) - return ERR_PTR(-EPERM); if (attr->max_entries == 0 || attr->key_size == 0 || (attr->value_size != sizeof(u32) && diff --git a/net/xdp/xskmap.c b/net/xdp/xskmap.c index 2c1427074a3b..e1c526f97ce3 100644 --- a/net/xdp/xskmap.c +++ b/net/xdp/xskmap.c @@ -5,7 +5,6 @@ #include #include -#include #include #include #include @@ -68,9 +67,6 @@ static struct bpf_map *xsk_map_alloc(union bpf_attr *attr) int numa_node; u64 size; - if (!capable(CAP_NET_ADMIN)) - return ERR_PTR(-EPERM); - if (attr->max_entries == 0 || attr->key_size != 4 || attr->value_size != 4 || attr->map_flags & ~(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)) diff --git a/tools/testing/selftests/bpf/prog_tests/unpriv_bpf_disabled.c b/tools/testing/selftests/bpf/prog_tests/unpriv_bpf_disabled.c index 8383a99f610f..0adf8d9475cb 100644 --- a/tools/testing/selftests/bpf/prog_tests/unpriv_bpf_disabled.c +++ b/tools/testing/selftests/bpf/prog_tests/unpriv_bpf_disabled.c @@ -171,7 +171,11 @@ static void test_unpriv_bpf_disabled_negative(struct test_unpriv_bpf_disabled *s prog_insns, prog_insn_cnt, &load_opts), -EPERM, "prog_load_fails"); - for (i = BPF_MAP_TYPE_HASH; i <= BPF_MAP_TYPE_BLOOM_FILTER; i++) + /* some map types require particular correct parameters which could be + * sanity-checked before enforcing -EPERM, so only validate that + * the simple ARRAY and HASH maps are failing with -EPERM + */ + for (i = BPF_MAP_TYPE_HASH; i <= BPF_MAP_TYPE_ARRAY; i++) ASSERT_EQ(bpf_map_create(i, NULL, sizeof(int), sizeof(int), 1, NULL), -EPERM, "map_create_fails");