From f0cfce64b6a061ffeafeda254734f0b1f2f452fd Mon Sep 17 00:00:00 2001 From: Steve Vinoski Date: Sun, 1 Mar 2015 12:33:20 -0500 Subject: Ensure NIF term creation disallows illegal values Add a check to enif_make_double to see if its double argument is infinity or NaN, returning a badarg exception if it is. Change the erl_nif documentation to specify that enif_make_double returns a badarg exception if its double argument is either infinity or NaN. Add tests to nif_SUITE for this change. Add checks to the enif_make* functions for atoms to prevent the creation of atoms whose name lengths are greater than the allowed maximum atom length. The enif_make_atom and enif_make_atom_len functions now return a badarg exception if the input string is too long. The enif_make_existing_atom and enif_make_existing_atom_len functions return false if the input string is too long. Change the erl_nif documentation to reflect the changes to these functions. Add tests to nif_SUITE for these changes. Add a field to ErlNifEnv to track that a NIF has raised an exception via enif_make_badarg. If a NIF calls enif_make_badarg but then ignores its return value and instead tries to return a non-exception term as its return value, the runtime still raises a badarg. This is needed to prevent enif_make_badarg values resulting from calls to enif_make_double, enif_make_atom, or enif_make_atom_len from being erroneously stored within other terms and returned from a NIF. Calling enif_make_badarg but not returning its return value has been documented as being illegal ever since enif_make_badarg was added, but the runtime has not enforced it until now. Add tests for regular and dirty NIFs to ensure that calls to enif_make_badarg result in badarg exceptions even if a NIF fails to return the result of enif_make_badarg as its return value. Add documentation to enif_make_badarg to specify that calling it raises a badarg even if a NIF ignores its return value. --- erts/emulator/beam/erl_nif.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) (limited to 'erts/emulator/beam/erl_nif.c') diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c index adc3520ebb..ec82ef251e 100644 --- a/erts/emulator/beam/erl_nif.c +++ b/erts/emulator/beam/erl_nif.c @@ -127,6 +127,7 @@ void erts_pre_nif(ErlNifEnv* env, Process* p, struct erl_module_nif* mod_nif) env->heap_frag = NULL; env->fpe_was_unmasked = erts_block_fpe(); env->tmp_obj_list = NULL; + env->exception_thrown = 0; } static void pre_nif_noproc(ErlNifEnv* env, struct erl_module_nif* mod_nif) @@ -742,6 +743,7 @@ Eterm enif_make_sub_binary(ErlNifEnv* env, ERL_NIF_TERM bin_term, Eterm enif_make_badarg(ErlNifEnv* env) { + env->exception_thrown = 1; BIF_ERROR(env->proc, BADARG); } @@ -964,7 +966,10 @@ ERL_NIF_TERM enif_make_uint64(ErlNifEnv* env, ErlNifUInt64 i) ERL_NIF_TERM enif_make_double(ErlNifEnv* env, double d) { - Eterm* hp = alloc_heap(env,FLOAT_SIZE_OBJECT); + Eterm* hp; + if (!isfinite(d)) + return enif_make_badarg(env); + hp = alloc_heap(env,FLOAT_SIZE_OBJECT); FloatDef f; f.fd = d; PUT_DOUBLE(f, hp); @@ -978,6 +983,8 @@ ERL_NIF_TERM enif_make_atom(ErlNifEnv* env, const char* name) ERL_NIF_TERM enif_make_atom_len(ErlNifEnv* env, const char* name, size_t len) { + if (len > MAX_ATOM_CHARACTERS) + return enif_make_badarg(env); return erts_atom_put((byte*)name, len, ERTS_ATOM_ENC_LATIN1, 1); } @@ -991,6 +998,8 @@ int enif_make_existing_atom_len(ErlNifEnv* env, const char* name, size_t len, ERL_NIF_TERM* atom, ErlNifCharEncoding encoding) { ASSERT(encoding == ERL_NIF_LATIN1); + if (len > MAX_ATOM_CHARACTERS) + return 0; return erts_atom_get(name, len, atom, ERTS_ATOM_ENC_LATIN1); } @@ -1754,14 +1763,13 @@ execute_dirty_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) ASSERT(ep); if (ep->fp) fp = NULL; - if (is_non_value(result)) { + if (is_non_value(result) || env->exception_thrown) { if (proc->freason != TRAP) { - ASSERT(proc->freason == BADARG); return init_nif_sched_data(env, dirty_nif_exception, fp, 0, argc, argv); } else { if (ep->fp == NULL) restore_nif_mfa(proc, ep, 1); - return result; + return THE_NON_VALUE; } } else -- cgit v1.2.3