[PATCH v3 net-next 01/12] selftests/bpf: add test for mixed signed and unsigned bounds checks
From: Edward Cree via iovisor-dev <hidden>
Date: 2017-06-27 12:57:23
Also in:
lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Linus Torvalds
Currently fails due to bug in verifier bounds handling. Signed-off-by: Edward Cree <ecree-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org> --- tools/testing/selftests/bpf/test_verifier.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index c0af019..fceed67 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c@@ -5279,6 +5279,32 @@ static struct bpf_test tests[] = { .errstr = "invalid bpf_context access", .prog_type = BPF_PROG_TYPE_LWT_IN, }, + { + "bounds checks mixing signed and unsigned", + .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, 7), + BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8), + BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16), + BPF_MOV64_IMM(BPF_REG_2, -1), + BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_2, 3), + BPF_JMP_IMM(BPF_JSGT, BPF_REG_1, 1, 2), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_ST_MEM(BPF_B, BPF_REG_0, 0, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map1 = { 3 }, + .errstr_unpriv = "R0 pointer arithmetic prohibited", + .errstr = "R0 min value is negative, either use unsigned index or do a if (index >=0) check.", + .result = REJECT, + .result_unpriv = REJECT, + }, }; static int probe_filter_length(const struct bpf_insn *fp)