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> --- 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 c7d25f23baf9..afa7e67f66e4 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -47,7 +47,7 @@ #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 @@ -64,6 +64,10 @@ struct bpf_test { int fixup_map2[MAX_FIXUPS]; int fixup_map3[MAX_FIXUPS]; int fixup_map4[MAX_FIXUPS]; + int fixup_map5[MAX_FIXUPS]; + int fixup_map6[MAX_FIXUPS]; + int fixup_map7[MAX_FIXUPS]; + int fixup_map8[MAX_FIXUPS]; int fixup_prog1[MAX_FIXUPS]; int fixup_prog2[MAX_FIXUPS]; int fixup_map_in_map[MAX_FIXUPS]; @@ -4391,6 +4395,85 @@ 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_map5 = { 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_map6 = { 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_map7 = { 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_map8 = { 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 = { @@ -12755,6 +12838,10 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog, int *fixup_map2 = test->fixup_map2; int *fixup_map3 = test->fixup_map3; int *fixup_map4 = test->fixup_map4; + int *fixup_map5 = test->fixup_map5; + int *fixup_map6 = test->fixup_map6; + int *fixup_map7 = test->fixup_map7; + int *fixup_map8 = test->fixup_map8; int *fixup_prog1 = test->fixup_prog1; int *fixup_prog2 = test->fixup_prog2; int *fixup_map_in_map = test->fixup_map_in_map; @@ -12843,6 +12930,38 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog, fixup_percpu_cgroup_storage++; } while (*fixup_percpu_cgroup_storage); } + if (*fixup_map5) { + map_fds[9] = create_map(BPF_MAP_TYPE_SOCKMAP, sizeof(int), + sizeof(int), 1); + do { + prog[*fixup_map5].imm = map_fds[9]; + fixup_map5++; + } while (*fixup_map5); + } + if (*fixup_map6) { + map_fds[10] = create_map(BPF_MAP_TYPE_SOCKHASH, sizeof(int), + sizeof(int), 1); + do { + prog[*fixup_map6].imm = map_fds[10]; + fixup_map6++; + } while (*fixup_map6); + } + if (*fixup_map7) { + map_fds[11] = create_map(BPF_MAP_TYPE_XSKMAP, sizeof(int), + sizeof(int), 1); + do { + prog[*fixup_map7].imm = map_fds[11]; + fixup_map7++; + } while (*fixup_map7); + } + if (*fixup_map8) { + map_fds[12] = create_map(BPF_MAP_TYPE_STACK_TRACE, sizeof(u32), + sizeof(u64), 1); + do { + prog[*fixup_map8].imm = map_fds[12]; + fixup_map8++; + } while (fixup_map8); + } } static void do_test_single(struct bpf_test *test, bool unpriv, -- 2.17.1