From: Jakub Sitnicki <jakub@cloudflare.com>
Date: Wed, 29 Apr 2020 20:11:53 +0200
Subject: selftests/bpf: Test that lookup on SOCKMAP/SOCKHASH is allowed
Patch-mainline: v5.8-rc1
Git-commit: 34a2cc6eee809f974111979f4c2b3c62aaaad457
References: bsc#1177028
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
Acked-by: Gary Lin <glin@suse.com>
---
tools/testing/selftests/bpf/verifier/prevent_map_lookup.c | 30 ------
tools/testing/selftests/bpf/verifier/sock.c | 70 ++++++++++++++
2 files changed, 70 insertions(+), 30 deletions(-)
--- a/tools/testing/selftests/bpf/verifier/prevent_map_lookup.c
+++ b/tools/testing/selftests/bpf/verifier/prevent_map_lookup.c
@@ -1,34 +1,4 @@
{
- "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 = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
--- 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,
+},