On 10/25/2018 5:54 PM, Naresh Kamboju wrote:

On Tue, 9 Oct 2018 at 12:32, Song Liu liu.song.a23@gmail.com wrote:

...

On Mon, Oct 8, 2018 at 6:07 PM Prashant Bhole bhole_prashant_q7@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_q7@lab.ntt.co.jp Acked-by: Alexei Starovoitov ast@kernel.org

Acked-by: Song Liu songliubraving@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);
  

•   }
  

selftests: bpf: test_verifier sockmap, sockhash, xskmap failed on mainline and next (from 4.19.0-rc7-next-20181011 to till date ) Are we missing any pre-required kernel configs ?

sockmap/hashmap is dependent on CONFIG_BPF_STREAM_PARSER and xskmap is dependent on CONFIG_XDP_SOCKETS.

Reference: include/linux/bpf_types.h

-Prashant

Test log,

selftests: bpf: test_verifier <> #274/p prevent map lookup in sockmap Failed to create hash map 'Invalid argument'! FAIL Unexpected error message! EXP: cannot pass map_type 15 into func bpf_map_lookup_elem RES: fd -1 is not pointing to valid bpf_map fd -1 is not pointing to valid bpf_map #275/p prevent map lookup in sockhash Failed to create hash map 'Invalid argument'! FAIL Unexpected error message! EXP: cannot pass map_type 18 into func bpf_map_lookup_elem RES: fd -1 is not pointing to valid bpf_map fd -1 is not pointing to valid bpf_map #276/p prevent map lookup in xskmap Failed to create hash map 'Invalid argument'! FAIL Unexpected error message! EXP: cannot pass map_type 17 into func bpf_map_lookup_elem RES: fd -1 is not pointing to valid bpf_map fd -1 is not pointing to valid bpf_map <> Summary: 962 PASSED, 0 SKIPPED, 3 FAILED not ok 1..1 selftests: bpf: test_verifier [FAIL] selftests: bpf_test_verifier [FAIL]

-mainline results history, https://qa-reports.linaro.org/lkft/linux-next-oe/tests/kselftest/bpf_test_ve...

-next results history, https://qa-reports.linaro.org/lkft/linux-next-oe/tests/kselftest/bpf_test_ve...

Test case full log, https://lkft.validation.linaro.org/scheduler/job/461881#L1655

Best regards Naresh Kamboju

...

...

•   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