On Mon, Oct 8, 2018 at 6:07 PM Prashant Bhole
<bhole_prashant...@lab.ntt.co.jp> wrote:
>
> 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 <bhole_prashant...@lab.ntt.co.jp>
> Acked-by: Alexei Starovoitov <a...@kernel.org>
Acked-by: Song Liu <songliubrav...@fb.com>
> ---
> 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,
> --
> 2.17.1
>
>
