selftests/bpf: Test that lookup on SOCKMAP/SOCKHASH is allowed

Now that bpf_map_lookup_elem() is white-listed for SOCKMAP/SOCKHASH,
replace the tests which check that verifier prevents lookup on these map
types with ones that ensure that lookup operation is permitted, but only
with a release of acquired socket reference.

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200429181154.479310-3-jakub@cloudflare.com

diff --git a/tools/testing/selftests/bpf/verifier/prevent_map_lookup.c b/tools/testing/selftests/bpf/verifier/prevent_map_lookup.c
index da7a4b37cb98d3d854e42005795a3dfa04679b2f..fc4e301260f6541849da4c3e0be0e238af7de922 100644 (file)
--- a/tools/testing/selftests/bpf/verifier/prevent_map_lookup.c
+++ b/tools/testing/selftests/bpf/verifier/prevent_map_lookup.c
@@ -1,33 +1,3 @@
-{
-       "prevent map lookup in sockmap",
-       .insns = {
-       BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-       BPF_LD_MAP_FD(BPF_REG_1, 0),
-       BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-       BPF_EXIT_INSN(),
-       },
-       .fixup_map_sockmap = { 3 },
-       .result = REJECT,
-       .errstr = "cannot pass map_type 15 into func bpf_map_lookup_elem",
-       .prog_type = BPF_PROG_TYPE_SOCK_OPS,
-},
-{
-       "prevent map lookup in sockhash",
-       .insns = {
-       BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-       BPF_LD_MAP_FD(BPF_REG_1, 0),
-       BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-       BPF_EXIT_INSN(),
-       },
-       .fixup_map_sockhash = { 3 },
-       .result = REJECT,
-       .errstr = "cannot pass map_type 18 into func bpf_map_lookup_elem",
-       .prog_type = BPF_PROG_TYPE_SOCK_OPS,
-},
 {
        "prevent map lookup in stack trace",
        .insns = {

diff --git a/tools/testing/selftests/bpf/verifier/sock.c b/tools/testing/selftests/bpf/verifier/sock.c
index 9ed192e14f5fe785613b1ecf5026fd0c499aec92..f87ad69dbc62fcf3d014dc44aade82fedcda65b9 100644 (file)
--- a/tools/testing/selftests/bpf/verifier/sock.c
+++ b/tools/testing/selftests/bpf/verifier/sock.c
@@ -516,3 +516,73 @@
        .prog_type = BPF_PROG_TYPE_XDP,
        .result = ACCEPT,
 },
+{
+       "bpf_map_lookup_elem(sockmap, &key)",
+       .insns = {
+       BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),
+       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
+       BPF_LD_MAP_FD(BPF_REG_1, 0),
+       BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+       BPF_MOV64_IMM(BPF_REG_0, 0),
+       BPF_EXIT_INSN(),
+       },
+       .fixup_map_sockmap = { 3 },
+       .prog_type = BPF_PROG_TYPE_SK_SKB,
+       .result = REJECT,
+       .errstr = "Unreleased reference id=2 alloc_insn=5",
+},
+{
+       "bpf_map_lookup_elem(sockhash, &key)",
+       .insns = {
+       BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),
+       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
+       BPF_LD_MAP_FD(BPF_REG_1, 0),
+       BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+       BPF_MOV64_IMM(BPF_REG_0, 0),
+       BPF_EXIT_INSN(),
+       },
+       .fixup_map_sockhash = { 3 },
+       .prog_type = BPF_PROG_TYPE_SK_SKB,
+       .result = REJECT,
+       .errstr = "Unreleased reference id=2 alloc_insn=5",
+},
+{
+       "bpf_map_lookup_elem(sockmap, &key); sk->type [fullsock field]; bpf_sk_release(sk)",
+       .insns = {
+       BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),
+       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
+       BPF_LD_MAP_FD(BPF_REG_1, 0),
+       BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+       BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+       BPF_EXIT_INSN(),
+       BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+       BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_sock, type)),
+       BPF_EMIT_CALL(BPF_FUNC_sk_release),
+       BPF_EXIT_INSN(),
+       },
+       .fixup_map_sockmap = { 3 },
+       .prog_type = BPF_PROG_TYPE_SK_SKB,
+       .result = ACCEPT,
+},
+{
+       "bpf_map_lookup_elem(sockhash, &key); sk->type [fullsock field]; bpf_sk_release(sk)",
+       .insns = {
+       BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),
+       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
+       BPF_LD_MAP_FD(BPF_REG_1, 0),
+       BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+       BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+       BPF_EXIT_INSN(),
+       BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+       BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_sock, type)),
+       BPF_EMIT_CALL(BPF_FUNC_sk_release),
+       BPF_EXIT_INSN(),
+       },
+       .fixup_map_sockhash = { 3 },
+       .prog_type = BPF_PROG_TYPE_SK_SKB,
+       .result = ACCEPT,
+},