From 7c85c448e7d74c4ddd759440a2141eab663567cf Mon Sep 17 00:00:00 2001 From: Prashant Bhole Date: Tue, 9 Oct 2018 10:04:54 +0900 Subject: [PATCH] selftests/bpf: test_verifier, check bpf_map_lookup_elem access in bpf prog map_lookup_elem isn't supported by certain map types like: - BPF_MAP_TYPE_PROG_ARRAY - BPF_MAP_TYPE_STACK_TRACE - BPF_MAP_TYPE_XSKMAP - BPF_MAP_TYPE_SOCKMAP/BPF_MAP_TYPE_SOCKHASH Let's add verfier tests to check whether verifier prevents bpf_map_lookup_elem call on above programs from bpf program. Signed-off-by: Prashant Bhole Acked-by: Alexei Starovoitov Acked-by: Song Liu Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/test_verifier.c | 121 +++++++++++++++++++- 1 file changed, 120 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 65ae44c85d27..cf4cd32b6772 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -48,7 +48,7 @@ #define MAX_INSNS BPF_MAXINSNS #define MAX_FIXUPS 8 -#define MAX_NR_MAPS 8 +#define MAX_NR_MAPS 13 #define POINTER_VALUE 0xcafe4all #define TEST_DATA_LEN 64 @@ -65,6 +65,10 @@ struct bpf_test { int fixup_map_hash_48b[MAX_FIXUPS]; int fixup_map_hash_16b[MAX_FIXUPS]; int fixup_map_array_48b[MAX_FIXUPS]; + int fixup_map_sockmap[MAX_FIXUPS]; + int fixup_map_sockhash[MAX_FIXUPS]; + int fixup_map_xskmap[MAX_FIXUPS]; + int fixup_map_stacktrace[MAX_FIXUPS]; int fixup_prog1[MAX_FIXUPS]; int fixup_prog2[MAX_FIXUPS]; int fixup_map_in_map[MAX_FIXUPS]; @@ -4541,6 +4545,85 @@ static struct bpf_test tests[] = { .errstr = "invalid access to packet", .prog_type = BPF_PROG_TYPE_SCHED_CLS, }, + { + "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 xskmap", + .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_xskmap = { 3 }, + .result = REJECT, + .errstr = "cannot pass map_type 17 into func bpf_map_lookup_elem", + .prog_type = BPF_PROG_TYPE_XDP, + }, + { + "prevent map lookup in stack trace", + .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_stacktrace = { 3 }, + .result = REJECT, + .errstr = "cannot pass map_type 7 into func bpf_map_lookup_elem", + .prog_type = BPF_PROG_TYPE_PERF_EVENT, + }, + { + "prevent map lookup in prog array", + .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_prog2 = { 3 }, + .result = REJECT, + .errstr = "cannot pass map_type 3 into func bpf_map_lookup_elem", + }, { "valid map access into an array with a constant", .insns = { @@ -13515,6 +13598,10 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_map_type prog_type, int *fixup_map_hash_48b = test->fixup_map_hash_48b; int *fixup_map_hash_16b = test->fixup_map_hash_16b; int *fixup_map_array_48b = test->fixup_map_array_48b; + int *fixup_map_sockmap = test->fixup_map_sockmap; + int *fixup_map_sockhash = test->fixup_map_sockhash; + int *fixup_map_xskmap = test->fixup_map_xskmap; + int *fixup_map_stacktrace = test->fixup_map_stacktrace; int *fixup_prog1 = test->fixup_prog1; int *fixup_prog2 = test->fixup_prog2; int *fixup_map_in_map = test->fixup_map_in_map; @@ -13603,6 +13690,38 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_map_type prog_type, fixup_percpu_cgroup_storage++; } while (*fixup_percpu_cgroup_storage); } + if (*fixup_map_sockmap) { + map_fds[9] = create_map(BPF_MAP_TYPE_SOCKMAP, sizeof(int), + sizeof(int), 1); + do { + prog[*fixup_map_sockmap].imm = map_fds[9]; + fixup_map_sockmap++; + } while (*fixup_map_sockmap); + } + if (*fixup_map_sockhash) { + map_fds[10] = create_map(BPF_MAP_TYPE_SOCKHASH, sizeof(int), + sizeof(int), 1); + do { + prog[*fixup_map_sockhash].imm = map_fds[10]; + fixup_map_sockhash++; + } while (*fixup_map_sockhash); + } + if (*fixup_map_xskmap) { + map_fds[11] = create_map(BPF_MAP_TYPE_XSKMAP, sizeof(int), + sizeof(int), 1); + do { + prog[*fixup_map_xskmap].imm = map_fds[11]; + fixup_map_xskmap++; + } while (*fixup_map_xskmap); + } + if (*fixup_map_stacktrace) { + map_fds[12] = create_map(BPF_MAP_TYPE_STACK_TRACE, sizeof(u32), + sizeof(u64), 1); + do { + prog[*fixup_map_stacktrace].imm = map_fds[12]; + fixup_map_stacktrace++; + } while (fixup_map_stacktrace); + } } static void do_test_single(struct bpf_test *test, bool unpriv,