From: Song Liu <songliubraving@fb.com>
To: <netdev@vger.kernel.org>
Cc: <ast@kernel.org>, <daniel@iogearbox.net>, <kernel-team@fb.com>,
Song Liu <songliubraving@fb.com>
Subject: [PATCH v4 bpf-next 2/2] bpf: add tests for direct packet access from CGROUP_SKB
Date: Thu, 18 Oct 2018 09:06:49 -0700 [thread overview]
Message-ID: <20181018160649.1611530-3-songliubraving@fb.com> (raw)
In-Reply-To: <20181018160649.1611530-1-songliubraving@fb.com>
Tests are added to make sure CGROUP_SKB cannot access:
tc_classid, data_meta, flow_keys
and can read and write:
mark, prority, and cb[0-4]
and can read other fields.
To make selftest with skb->sk work, a dummy sk is added in
bpf_prog_test_run_skb().
Signed-off-by: Song Liu <songliubraving@fb.com>
---
net/bpf/test_run.c | 7 +
tools/testing/selftests/bpf/test_verifier.c | 170 ++++++++++++++++++++
2 files changed, 177 insertions(+)
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 0c423b8cd75c..8dccac305268 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -10,6 +10,8 @@
#include <linux/etherdevice.h>
#include <linux/filter.h>
#include <linux/sched/signal.h>
+#include <net/sock.h>
+#include <net/tcp.h>
static __always_inline u32 bpf_test_run_one(struct bpf_prog *prog, void *ctx,
struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE])
@@ -115,6 +117,7 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
u32 retval, duration;
int hh_len = ETH_HLEN;
struct sk_buff *skb;
+ struct sock sk = {0};
void *data;
int ret;
@@ -137,11 +140,15 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
break;
}
+ sock_net_set(&sk, &init_net);
+ sock_init_data(NULL, &sk);
+
skb = build_skb(data, 0);
if (!skb) {
kfree(data);
return -ENOMEM;
}
+ skb->sk = &sk;
skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
__skb_put(skb, size);
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index cf4cd32b6772..5bfba7e8afd7 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -4862,6 +4862,176 @@ static struct bpf_test tests[] = {
.result = REJECT,
.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
},
+ {
+ "direct packet read test#1 for CGROUP_SKB",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+ offsetof(struct __sk_buff, data)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+ offsetof(struct __sk_buff, data_end)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1,
+ offsetof(struct __sk_buff, len)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1,
+ offsetof(struct __sk_buff, pkt_type)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct __sk_buff, mark)),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_6,
+ offsetof(struct __sk_buff, mark)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1,
+ offsetof(struct __sk_buff, queue_mapping)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_1,
+ offsetof(struct __sk_buff, protocol)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_1,
+ offsetof(struct __sk_buff, vlan_present)),
+ BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
+ BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
+ BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_2, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+ },
+ {
+ "direct packet read test#2 for CGROUP_SKB",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1,
+ offsetof(struct __sk_buff, vlan_tci)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1,
+ offsetof(struct __sk_buff, vlan_proto)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct __sk_buff, priority)),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_6,
+ offsetof(struct __sk_buff, priority)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1,
+ offsetof(struct __sk_buff, ingress_ifindex)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_1,
+ offsetof(struct __sk_buff, tc_index)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_1,
+ offsetof(struct __sk_buff, hash)),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+ },
+ {
+ "direct packet read test#3 for CGROUP_SKB",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1,
+ offsetof(struct __sk_buff, cb[0])),
+ BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1,
+ offsetof(struct __sk_buff, cb[1])),
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct __sk_buff, cb[2])),
+ BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1,
+ offsetof(struct __sk_buff, cb[3])),
+ BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_1,
+ offsetof(struct __sk_buff, cb[4])),
+ BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_1,
+ offsetof(struct __sk_buff, napi_id)),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_4,
+ offsetof(struct __sk_buff, cb[0])),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_5,
+ offsetof(struct __sk_buff, cb[1])),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_6,
+ offsetof(struct __sk_buff, cb[2])),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_7,
+ offsetof(struct __sk_buff, cb[3])),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_8,
+ offsetof(struct __sk_buff, cb[4])),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+ },
+ {
+ "direct packet read test#4 for CGROUP_SKB",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+ offsetof(struct __sk_buff, family)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+ offsetof(struct __sk_buff, remote_ip4)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1,
+ offsetof(struct __sk_buff, local_ip4)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1,
+ offsetof(struct __sk_buff, remote_ip6[0])),
+ BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1,
+ offsetof(struct __sk_buff, remote_ip6[1])),
+ BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1,
+ offsetof(struct __sk_buff, remote_ip6[2])),
+ BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1,
+ offsetof(struct __sk_buff, remote_ip6[3])),
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct __sk_buff, local_ip6[0])),
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct __sk_buff, local_ip6[1])),
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct __sk_buff, local_ip6[2])),
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct __sk_buff, local_ip6[3])),
+ BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1,
+ offsetof(struct __sk_buff, remote_port)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_1,
+ offsetof(struct __sk_buff, local_port)),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+ },
+ {
+ "invalid access of tc_classid for CGROUP_SKB",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+ offsetof(struct __sk_buff, tc_classid)),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = REJECT,
+ .errstr = "invalid bpf_context access",
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+ },
+ {
+ "invalid access of data_meta for CGROUP_SKB",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+ offsetof(struct __sk_buff, data_meta)),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = REJECT,
+ .errstr = "invalid bpf_context access",
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+ },
+ {
+ "invalid access of flow_keys for CGROUP_SKB",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+ offsetof(struct __sk_buff, flow_keys)),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = REJECT,
+ .errstr = "invalid bpf_context access",
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+ },
+ {
+ "invalid write access to napi_id for CGROUP_SKB",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_1,
+ offsetof(struct __sk_buff, napi_id)),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_9,
+ offsetof(struct __sk_buff, napi_id)),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = REJECT,
+ .errstr = "invalid bpf_context access",
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+ },
{
"valid cgroup storage access",
.insns = {
--
2.17.1
next prev parent reply other threads:[~2018-10-19 0:08 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-18 16:06 [PATCH v4 bpf-next 0/2] bpf: add cg_skb_is_valid_access Song Liu
2018-10-18 16:06 ` [PATCH v4 bpf-next 1/2] bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB Song Liu
2018-10-19 0:14 ` Daniel Borkmann
2018-10-19 1:33 ` Alexei Starovoitov
2018-10-19 2:03 ` Alexei Starovoitov
2018-10-18 16:06 ` Song Liu [this message]
2018-10-18 23:34 ` [PATCH v4 bpf-next 0/2] bpf: add cg_skb_is_valid_access Alexei Starovoitov
2018-10-19 1:46 ` Alexei Starovoitov
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