From 59a0e4bd8391962f62600ae3ac95ab0fba74d464 Mon Sep 17 00:00:00 2001 From: law Date: Thu, 4 Aug 2016 16:53:18 +0000 Subject: [PATCH] Fix for PR71696 in Libiberty Demangler MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [BZ #71696] -- https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71696 2016-08-04 Marcel Böhme PR c++/71696 * cplus-dem.c: Prevent infinite recursion when there is a cycle in the referencing of remembered mangled types. (work_stuff): New stack to keep track of the remembered mangled types that are currently being processed. (push_processed_type): New method to push currently processed remembered type onto the stack. (pop_processed_type): New method to pop currently processed remembered type from the stack. (work_stuff_copy_to_from): Copy values of new variables. (delete_non_B_K_work_stuff): Free stack memory. (demangle_args): Push/Pop currently processed remembered type. (do_type): Do not demangle a cyclic reference and push/pop referenced remembered type. cherry-picked from commit of git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@239143 138bc75d-0d04-0410-961f-82ee72b054a4 Upstream-Status: Backport [master] CVE: CVE-2016-6131 Signed-off-by: Yuanjie Huang --- libiberty/ChangeLog | 17 ++++++++ libiberty/cplus-dem.c | 78 ++++++++++++++++++++++++++++++++--- libiberty/testsuite/demangle-expected | 18 ++++++++ 3 files changed, 108 insertions(+), 5 deletions(-) Index: gcc-6.4.0/libiberty/cplus-dem.c =================================================================== --- gcc-6.4.0.orig/libiberty/cplus-dem.c +++ gcc-6.4.0/libiberty/cplus-dem.c @@ -144,6 +144,9 @@ struct work_stuff string* previous_argument; /* The last function argument demangled. */ int nrepeats; /* The number of times to repeat the previous argument. */ + int *proctypevec; /* Indices of currently processed remembered typevecs. */ + int proctypevec_size; + int nproctypes; }; #define PRINT_ANSI_QUALIFIERS (work -> options & DMGL_ANSI) @@ -435,6 +438,10 @@ iterate_demangle_function (struct work_s static void remember_type (struct work_stuff *, const char *, int); +static void push_processed_type (struct work_stuff *, int); + +static void pop_processed_type (struct work_stuff *); + static void remember_Btype (struct work_stuff *, const char *, int, int); static int register_Btype (struct work_stuff *); @@ -1301,6 +1308,10 @@ work_stuff_copy_to_from (struct work_stu memcpy (to->btypevec[i], from->btypevec[i], len); } + if (from->proctypevec) + to->proctypevec = + XDUPVEC (int, from->proctypevec, from->proctypevec_size); + if (from->ntmpl_args) to->tmpl_argvec = XNEWVEC (char *, from->ntmpl_args); @@ -1329,11 +1340,17 @@ delete_non_B_K_work_stuff (struct work_s /* Discard the remembered types, if any. */ forget_types (work); - if (work -> typevec != NULL) + if (work->typevec != NULL) { - free ((char *) work -> typevec); - work -> typevec = NULL; - work -> typevec_size = 0; + free ((char *) work->typevec); + work->typevec = NULL; + work->typevec_size = 0; + } + if (work->proctypevec != NULL) + { + free (work->proctypevec); + work->proctypevec = NULL; + work->proctypevec_size = 0; } if (work->tmpl_argvec) { @@ -3552,6 +3569,8 @@ static int do_type (struct work_stuff *work, const char **mangled, string *result) { int n; + int i; + int is_proctypevec; int done; int success; string decl; @@ -3564,6 +3583,7 @@ do_type (struct work_stuff *work, const done = 0; success = 1; + is_proctypevec = 0; while (success && !done) { int member; @@ -3616,8 +3636,15 @@ do_type (struct work_stuff *work, const success = 0; } else + for (i = 0; i < work->nproctypes; i++) + if (work -> proctypevec [i] == n) + success = 0; + + if (success) { - remembered_type = work -> typevec[n]; + is_proctypevec = 1; + push_processed_type (work, n); + remembered_type = work->typevec[n]; mangled = &remembered_type; } break; @@ -3840,6 +3867,9 @@ do_type (struct work_stuff *work, const string_delete (result); string_delete (&decl); + if (is_proctypevec) + pop_processed_type (work); + if (success) /* Assume an integral type, if we're not sure. */ return (int) ((tk == tk_none) ? tk_integral : tk); @@ -4252,6 +4282,41 @@ do_arg (struct work_stuff *work, const c } static void +push_processed_type (struct work_stuff *work, int typevec_index) +{ + if (work->nproctypes >= work->proctypevec_size) + { + if (!work->proctypevec_size) + { + work->proctypevec_size = 4; + work->proctypevec = XNEWVEC (int, work->proctypevec_size); + } + else + { + if (work->proctypevec_size < 16) + /* Double when small. */ + work->proctypevec_size *= 2; + else + { + /* Grow slower when large. */ + if (work->proctypevec_size > (INT_MAX / 3) * 2) + xmalloc_failed (INT_MAX); + work->proctypevec_size = (work->proctypevec_size * 3 / 2); + } + work->proctypevec + = XRESIZEVEC (int, work->proctypevec, work->proctypevec_size); + } + } + work->proctypevec [work->nproctypes++] = typevec_index; +} + +static void +pop_processed_type (struct work_stuff *work) +{ + work->nproctypes--; +} + +static void remember_type (struct work_stuff *work, const char *start, int len) { char *tem; @@ -4515,10 +4580,13 @@ demangle_args (struct work_stuff *work, { string_append (declp, ", "); } + push_processed_type (work, t); if (!do_arg (work, &tem, &arg)) { + pop_processed_type (work); return (0); } + pop_processed_type (work); if (PRINT_ARG_TYPES) { string_appends (declp, &arg); Index: gcc-6.4.0/libiberty/testsuite/demangle-expected =================================================================== --- gcc-6.4.0.orig/libiberty/testsuite/demangle-expected +++ gcc-6.4.0/libiberty/testsuite/demangle-expected @@ -4491,3 +4491,21 @@ void eat()::{lambda(short*, auto:1*, auto:2*)#2}>(int*&, void Bar()::{lambda(short*, auto:1*, auto:2*)#2}&) +# +# Tests write access violation PR70926 + +0__Ot2m02R5T0000500000 +0__Ot2m02R5T0000500000 +# + +0__GT50000000000_ +0__GT50000000000_ +# + +__t2m05B500000000000000000_ +__t2m05B500000000000000000_ +# +# Tests stack overflow PR71696 + +__10%0__S4_0T0T0 +%0<>::%0(%0<>)