diff options
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/var_off.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/verifier/var_off.c b/tools/testing/selftests/bpf/verifier/var_off.c index c4ebd0bb0781..3840bd16e173 100644 --- a/tools/testing/selftests/bpf/verifier/var_off.c +++ b/tools/testing/selftests/bpf/verifier/var_off.c @@ -115,6 +115,33 @@ .prog_type = BPF_PROG_TYPE_LWT_IN, }, { + "indirect variable-offset stack access, uninitialized", + .insns = { + BPF_MOV64_IMM(BPF_REG_2, 6), + BPF_MOV64_IMM(BPF_REG_3, 28), + /* Fill the top 16 bytes of the stack. */ + BPF_ST_MEM(BPF_W, BPF_REG_10, -16, 0), + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + /* Get an unknown value. */ + BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1, 0), + /* Make it small and 4-byte aligned. */ + BPF_ALU64_IMM(BPF_AND, BPF_REG_4, 4), + BPF_ALU64_IMM(BPF_SUB, BPF_REG_4, 16), + /* Add it to fp. We now have either fp-12 or fp-16, we don't know + * which, but either way it points to initialized stack. + */ + BPF_ALU64_REG(BPF_ADD, BPF_REG_4, BPF_REG_10), + BPF_MOV64_IMM(BPF_REG_5, 8), + /* Dereference it indirectly. */ + BPF_EMIT_CALL(BPF_FUNC_getsockopt), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "invalid indirect read from stack var_off", + .result = REJECT, + .prog_type = BPF_PROG_TYPE_SOCK_OPS, +}, +{ "indirect variable-offset stack access, ok", .insns = { /* Fill the top 16 bytes of the stack. */ |