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| author |   Alexei Starovoitov <ast@fb.com> | 2017-08-23 15:10:26 +0100 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-08-23 22:38:07 -0700 |
| commit | df20cb7ec17577c94ef93fa86c7c80958046a01e (patch) | |
| tree | fdcb349d3344c82114390386044a36da5c8a90da /tools | |
| parent | bpf/verifier: when pruning a branch, ignore its write marks (diff) | |
| download | linux-dev-df20cb7ec17577c94ef93fa86c7c80958046a01e.tar.xz linux-dev-df20cb7ec17577c94ef93fa86c7c80958046a01e.zip | |
selftests/bpf: add a test for a pruning bug in the verifier
The test makes a read through a map value pointer, then considers pruning
a branch where the register holds an adjusted map value pointer. It
should not prune, but currently it does.
Signed-off-by: Alexei Starovoitov <ast@fb.com>
[ecree@solarflare.com: added test-name and patch description]
Signed-off-by: Edward Cree <ecree@solarflare.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/bpf/test_verifier.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index c912734d2364..353d17015641 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -6503,6 +6503,34 @@ static struct bpf_test tests[] = { .result = REJECT, .prog_type = BPF_PROG_TYPE_LWT_IN, }, + { + "varlen_map_value_access pruning", + .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_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 8), + BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0), + BPF_MOV32_IMM(BPF_REG_2, MAX_ENTRIES), + BPF_JMP_REG(BPF_JSGT, BPF_REG_2, BPF_REG_1, 1), + BPF_MOV32_IMM(BPF_REG_1, 0), + BPF_ALU32_IMM(BPF_LSH, BPF_REG_1, 2), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_JMP_IMM(BPF_JA, 0, 0, 0), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, + offsetof(struct test_val, foo)), + BPF_EXIT_INSN(), + }, + .fixup_map2 = { 3 }, + .errstr_unpriv = "R0 leaks addr", + .errstr = "R0 unbounded memory access", + .result_unpriv = REJECT, + .result = REJECT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, + }, }; static int probe_filter_length(const struct bpf_insn *fp) |