From 2cb494a36c98279c5c6ce8e99cf9776f15449ade Mon Sep 17 00:00:00 2001 From: Song Liu Date: Fri, 19 Oct 2018 09:57:58 -0700 Subject: bpf: add tests for direct packet access from CGROUP_SKB 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 Signed-off-by: Alexei Starovoitov --- net/bpf/test_run.c | 15 +++ tools/testing/selftests/bpf/test_verifier.c | 171 ++++++++++++++++++++++++++++ 2 files changed, 186 insertions(+) diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 0c423b8cd75c..c89c22c49015 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -10,6 +10,8 @@ #include #include #include +#include +#include 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; void *data; int ret; @@ -137,11 +140,21 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, break; } + sk = kzalloc(sizeof(struct sock), GFP_USER); + if (!sk) { + kfree(data); + return -ENOMEM; + } + sock_net_set(sk, current->nsproxy->net_ns); + sock_init_data(NULL, sk); + skb = build_skb(data, 0); if (!skb) { kfree(data); + kfree(sk); return -ENOMEM; } + skb->sk = sk; skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN); __skb_put(skb, size); @@ -159,6 +172,7 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, if (pskb_expand_head(skb, nhead, 0, GFP_USER)) { kfree_skb(skb); + kfree(sk); return -ENOMEM; } } @@ -171,6 +185,7 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, size = skb_headlen(skb); ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration); kfree_skb(skb); + kfree(sk); return ret; } diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index cf4cd32b6772..f1ae8d09770f 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -4862,6 +4862,177 @@ 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 = { -- cgit v1.2.3