From 6fe6bd7c0860961bfa4a705974bce6b9ec31edeb Mon Sep 17 00:00:00 2001 From: Nick Clifton Date: Wed, 10 Apr 2019 14:44:47 +0000 Subject: [PATCH] Fix a stack exhaustion bug in libiberty's demangler when decoding a pathalogically constructed mangled name. PR 89394 * cp-demangle.c (cplus_demangle_fill_name): Reject negative lengths. (d_count_templates_scopes): Replace num_templates and num_scopes parameters with a struct d_print_info pointer parameter. Adjust body of the function accordingly. Add recursion counter and check that the recursion limit is not reached. (d_print_init): Pass dpi parameter to d_count_templates_scopes. Reset recursion counter afterwards, unless the recursion limit was reached. From-SVN: r270258 --- libiberty/ChangeLog | 13 +++++++++++ libiberty/cp-demangle.c | 48 ++++++++++++++++++++++------------------- 2 files changed, 39 insertions(+), 22 deletions(-) diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog index 031be3a974a..06ff39a2656 100644 --- a/libiberty/ChangeLog +++ b/libiberty/ChangeLog @@ -1,3 +1,16 @@ +2019-04-10 Nick Clifton + + PR 89394 + * cp-demangle.c (cplus_demangle_fill_name): Reject negative + lengths. + (d_count_templates_scopes): Replace num_templates and num_scopes + parameters with a struct d_print_info pointer parameter. Adjust + body of the function accordingly. Add recursion counter and check + that the recursion limit is not reached. + (d_print_init): Pass dpi parameter to d_count_templates_scopes. + Reset recursion counter afterwards, unless the recursion limit was + reached. + 2019-04-07 Alan Modra * functions.texi: Regenerate. diff --git a/libiberty/cp-demangle.c b/libiberty/cp-demangle.c index b34b4856922..779b4e763a0 100644 --- a/libiberty/cp-demangle.c +++ b/libiberty/cp-demangle.c @@ -861,7 +861,7 @@ CP_STATIC_IF_GLIBCPP_V3 int cplus_demangle_fill_name (struct demangle_component *p, const char *s, int len) { - if (p == NULL || s == NULL || len == 0) + if (p == NULL || s == NULL || len <= 0) return 0; p->d_printing = 0; p->type = DEMANGLE_COMPONENT_NAME; @@ -4061,7 +4061,7 @@ d_growable_string_callback_adapter (const char *s, size_t l, void *opaque) are larger than the actual numbers encountered. */ static void -d_count_templates_scopes (int *num_templates, int *num_scopes, +d_count_templates_scopes (struct d_print_info *dpi, const struct demangle_component *dc) { if (dc == NULL) @@ -4081,13 +4081,13 @@ d_count_templates_scopes (int *num_templates, int *num_scopes, break; case DEMANGLE_COMPONENT_TEMPLATE: - (*num_templates)++; + dpi->num_copy_templates++; goto recurse_left_right; case DEMANGLE_COMPONENT_REFERENCE: case DEMANGLE_COMPONENT_RVALUE_REFERENCE: if (d_left (dc)->type == DEMANGLE_COMPONENT_TEMPLATE_PARAM) - (*num_scopes)++; + dpi->num_saved_scopes++; goto recurse_left_right; case DEMANGLE_COMPONENT_QUAL_NAME: @@ -4152,42 +4152,42 @@ d_count_templates_scopes (int *num_templates, int *num_scopes, case DEMANGLE_COMPONENT_TAGGED_NAME: case DEMANGLE_COMPONENT_CLONE: recurse_left_right: - d_count_templates_scopes (num_templates, num_scopes, - d_left (dc)); - d_count_templates_scopes (num_templates, num_scopes, - d_right (dc)); + /* PR 89394 - Check for too much recursion. */ + if (dpi->recursion > DEMANGLE_RECURSION_LIMIT) + /* FIXME: There ought to be a way to report to the + user that the recursion limit has been reached. */ + return; + + ++ dpi->recursion; + d_count_templates_scopes (dpi, d_left (dc)); + d_count_templates_scopes (dpi, d_right (dc)); + -- dpi->recursion; break; case DEMANGLE_COMPONENT_CTOR: - d_count_templates_scopes (num_templates, num_scopes, - dc->u.s_ctor.name); + d_count_templates_scopes (dpi, dc->u.s_ctor.name); break; case DEMANGLE_COMPONENT_DTOR: - d_count_templates_scopes (num_templates, num_scopes, - dc->u.s_dtor.name); + d_count_templates_scopes (dpi, dc->u.s_dtor.name); break; case DEMANGLE_COMPONENT_EXTENDED_OPERATOR: - d_count_templates_scopes (num_templates, num_scopes, - dc->u.s_extended_operator.name); + d_count_templates_scopes (dpi, dc->u.s_extended_operator.name); break; case DEMANGLE_COMPONENT_FIXED_TYPE: - d_count_templates_scopes (num_templates, num_scopes, - dc->u.s_fixed.length); + d_count_templates_scopes (dpi, dc->u.s_fixed.length); break; case DEMANGLE_COMPONENT_GLOBAL_CONSTRUCTORS: case DEMANGLE_COMPONENT_GLOBAL_DESTRUCTORS: - d_count_templates_scopes (num_templates, num_scopes, - d_left (dc)); + d_count_templates_scopes (dpi, d_left (dc)); break; case DEMANGLE_COMPONENT_LAMBDA: case DEMANGLE_COMPONENT_DEFAULT_ARG: - d_count_templates_scopes (num_templates, num_scopes, - dc->u.s_unary_num.sub); + d_count_templates_scopes (dpi, dc->u.s_unary_num.sub); break; } } @@ -4222,8 +4222,12 @@ d_print_init (struct d_print_info *dpi, demangle_callbackref callback, dpi->next_copy_template = 0; dpi->num_copy_templates = 0; - d_count_templates_scopes (&dpi->num_copy_templates, - &dpi->num_saved_scopes, dc); + d_count_templates_scopes (dpi, dc); + /* If we did not reach the recursion limit, then reset the + current recursion value back to 0, so that we can print + the templates. */ + if (dpi->recursion < DEMANGLE_RECURSION_LIMIT) + dpi->recursion = 0; dpi->num_copy_templates *= dpi->num_saved_scopes; dpi->current_template = NULL; -- 2.30.2