From 29200c199cc9bde59033ab30fcc40b6c8ae630b0 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 3 Feb 2017 16:25:23 -0500 Subject: bpf: test for AND edge cases These two tests are based on the work done for f23cc643f9ba. The first test is just a basic one to make sure we don't allow AND'ing negative values, even if it would result in a valid index for the array. The second is a cleaned up version of the original testcase provided by Jann Horn that resulted in the commit. Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: Josef Bacik Signed-off-by: David S. Miller --- tools/testing/selftests/bpf/test_verifier.c | 55 +++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 0d0912c..df194e1 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -4370,6 +4370,61 @@ static struct bpf_test tests[] = { .result = ACCEPT, .prog_type = BPF_PROG_TYPE_TRACEPOINT, }, + { + "invalid and of negative number", + .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, 4), + BPF_MOV64_IMM(BPF_REG_1, 6), + BPF_ALU64_IMM(BPF_AND, BPF_REG_1, -4), + BPF_ALU64_IMM(BPF_LSH, BPF_REG_1, 2), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, + offsetof(struct test_val, foo)), + BPF_EXIT_INSN(), + }, + .fixup_map2 = { 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, + }, + { + "invalid range check", + .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, 12), + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_9, 1), + BPF_ALU32_IMM(BPF_MOD, BPF_REG_1, 2), + BPF_ALU32_IMM(BPF_ADD, BPF_REG_1, 1), + BPF_ALU32_REG(BPF_AND, BPF_REG_9, BPF_REG_1), + BPF_ALU32_IMM(BPF_ADD, BPF_REG_9, 1), + BPF_ALU32_IMM(BPF_RSH, BPF_REG_9, 1), + BPF_MOV32_IMM(BPF_REG_3, 1), + BPF_ALU32_REG(BPF_SUB, BPF_REG_3, BPF_REG_9), + BPF_ALU32_IMM(BPF_MUL, BPF_REG_3, 0x10000000), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_3), + BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_3, 0), + BPF_MOV64_REG(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map2 = { 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) -- cgit v1.1