From 6e00c6f9103a967d02ea137b7154bdedf02f5b49 Mon Sep 17 00:00:00 2001 From: Paul Pluzhnikov Date: Sat, 1 Sep 2018 10:50:41 -0700 Subject: [PATCH] BZ #20544 assert on NULL fn in atexit, etc. --- ChangeLog | 8 +++++ stdlib/Makefile | 2 +- stdlib/cxa_atexit.c | 4 +++ stdlib/on_exit.c | 5 +++ stdlib/tst-bz20544.c | 72 ++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 90 insertions(+), 1 deletion(-) create mode 100644 stdlib/tst-bz20544.c diff --git a/ChangeLog b/ChangeLog index 837c167a0b..59d4b9d0c0 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2018-11-13 Paul Pluzhnikov + + [BZ #20544] + * stdlib/cxa_atexit.c (__internal_atexit): assert func != NULL. + * stdlib/on_exit.c (__on_exit): Likewise. + * stdlib/Makefile (tests): Add tst-bz20544. + * stdlib/tst-bz20544.c: New test. + 2018-11-13 Florian Weimer * malloc/malloc.c (fastbin_push_entry): New function. diff --git a/stdlib/Makefile b/stdlib/Makefile index 98dbddc43c..8bce89fffe 100644 --- a/stdlib/Makefile +++ b/stdlib/Makefile @@ -87,7 +87,7 @@ tests := tst-strtol tst-strtod testmb testrand testsort testdiv \ tst-makecontext-align test-bz22786 tst-strtod-nan-sign \ tst-swapcontext1 tst-setcontext4 tst-setcontext5 \ tst-setcontext6 tst-setcontext7 tst-setcontext8 \ - tst-setcontext9 + tst-setcontext9 tst-bz20544 tests-internal := tst-strtod1i tst-strtod3 tst-strtod4 tst-strtod5i \ tst-tls-atexit tst-tls-atexit-nodelete diff --git a/stdlib/cxa_atexit.c b/stdlib/cxa_atexit.c index 6d65f7e615..c1f146bfee 100644 --- a/stdlib/cxa_atexit.c +++ b/stdlib/cxa_atexit.c @@ -36,6 +36,10 @@ __internal_atexit (void (*func) (void *), void *arg, void *d, { struct exit_function *new; + /* As a QoI issue we detect NULL early with an assertion instead + of a SIGSEGV at program exit when the handler is run. BZ#20544 */ + assert (func != NULL); + __libc_lock_lock (__exit_funcs_lock); new = __new_exitfn (listp); diff --git a/stdlib/on_exit.c b/stdlib/on_exit.c index 5241e0d86f..a8be62c513 100644 --- a/stdlib/on_exit.c +++ b/stdlib/on_exit.c @@ -15,6 +15,7 @@ License along with the GNU C Library; if not, see . */ +#include #include #include "exit.h" #include @@ -25,6 +26,10 @@ __on_exit (void (*func) (int status, void *arg), void *arg) { struct exit_function *new; + /* As a QoI issue we detect NULL early with an assertion instead + of a SIGSEGV at program exit when the handler is run. BZ#20544 */ + assert (func != NULL); + __libc_lock_lock (__exit_funcs_lock); new = __new_exitfn (&__exit_funcs); diff --git a/stdlib/tst-bz20544.c b/stdlib/tst-bz20544.c new file mode 100644 index 0000000000..f3b08531bd --- /dev/null +++ b/stdlib/tst-bz20544.c @@ -0,0 +1,72 @@ +/* Verify atexit, on_exit, etc. abort on NULL function pointer. + Copyright (C) 2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + + +#include +#include +#include +#include +#include +#include + +extern int __cxa_atexit (void (*func) (void *), void *arg, void *d); + +#pragma GCC diagnostic ignored "-Wnonnull" + +static int +do_test (void) +{ +#if defined(NDEBUG) + FAIL_UNSUPPORTED("Assertions disabled (NDEBUG). " + "Can't verify that assertions fire."); +#else + int j; + + for (j = 0; j < 3; j++) { + pid_t pid = xfork (); + if (pid == 0) { + /* Child. */ + switch (j) { + case 0: + atexit (NULL); /* Should assert. */ + exit (EXIT_FAILURE); + case 1: + on_exit (NULL, NULL); /* Should assert. */ + exit (EXIT_FAILURE); + case 2: + __cxa_atexit (NULL, NULL, NULL); /* Should assert. */ + exit (EXIT_FAILURE); + default: + /* We shouldn't be here. */ + exit (EXIT_FAILURE); + } + } else { + /* Parent. Verify child exited with SIGABRT. */ + int status; + + TEST_VERIFY (pid == xwaitpid (pid, &status, 0)); + TEST_VERIFY (WIFSIGNALED (status)); + TEST_VERIFY (WTERMSIG (status) == SIGABRT); + } + } +#endif /* NDEBUG */ + + return 0; +} + +#include -- 2.19.1.930.g4563a0d9d0-goog