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authorSong Liu <songliubraving@fb.com>2018-10-19 09:57:58 -0700
committerAlexei Starovoitov <ast@kernel.org>2018-10-19 13:49:34 -0700
commit2cb494a36c98279c5c6ce8e99cf9776f15449ade (patch)
treec8a67095d219b652a8eea067188bff6c599e6881
parentb39b5f411dcfce28ff954e5d6acb2c11be3cb0ec (diff)
downloadlinux-2cb494a36c98279c5c6ce8e99cf9776f15449ade.tar.bz2
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 <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
-rw-r--r--net/bpf/test_run.c15
-rw-r--r--tools/testing/selftests/bpf/test_verifier.c171
2 files changed, 186 insertions, 0 deletions
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 <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;
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
@@ -4863,6 +4863,177 @@ static struct bpf_test tests[] = {
.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 = {
BPF_MOV64_IMM(BPF_REG_2, 0),