diff options
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | malloc/Makefile | 2 | ||||
| -rw-r--r-- | malloc/tst-tcfree3.c | 56 |
3 files changed, 63 insertions, 1 deletions
@@ -1,3 +1,9 @@ +2018-12-07 DJ Delorie <dj@redhat.com> + + [BZ #23907] + * malloc/tst-tcfree3.c: New. + * malloc/Makefile: Add it. + 2018-12-07 H.J. Lu <hongjiu.lu@intel.com> * include/sched.h (__getcpu): Don't use __typeof__ (getcpu). diff --git a/malloc/Makefile b/malloc/Makefile index e6dfbfc..388cf7e 100644 --- a/malloc/Makefile +++ b/malloc/Makefile @@ -38,7 +38,7 @@ tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \ tst-malloc_info \ tst-malloc-too-large \ tst-malloc-stats-cancellation \ - tst-tcfree1 tst-tcfree2 \ + tst-tcfree1 tst-tcfree2 tst-tcfree3 \ tests-static := \ tst-interpose-static-nothread \ diff --git a/malloc/tst-tcfree3.c b/malloc/tst-tcfree3.c new file mode 100644 index 0000000..016d30d --- /dev/null +++ b/malloc/tst-tcfree3.c @@ -0,0 +1,56 @@ +/* Test that malloc tcache catches double free. + 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 + <http://www.gnu.org/licenses/>. */ + +#include <malloc.h> +#include <string.h> + +/* Prevent GCC from optimizing away any malloc/free pairs. */ +#pragma GCC optimize ("O0") + +static int +do_test (void) +{ + /* Do two allocation of any size that fit in tcache, and one that + doesn't. */ + int ** volatile a = malloc (32); + int ** volatile b = malloc (32); + /* This is just under the mmap threshold. */ + int ** volatile c = malloc (127 * 1024); + + /* The invalid "tcache bucket" we might dereference will likely end + up somewhere within this memory block, so make all the accidental + "next" pointers cause segfaults. BZ #23907. */ + memset (c, 0xff, 127 * 1024); + + free (a); // puts in tcache + + /* A is now free and contains the key we use to detect in-tcache. + Copy the key to the other chunks. */ + memcpy (b, a, 32); + memcpy (c, a, 32); + + /* This free tests the "are we in the tcache already" loop with a + VALID bin but "coincidental" matching key. */ + free (b); // should NOT abort + /* This free tests the "is it a valid tcache bin" test. */ + free (c); // should NOT abort + + return 0; +} + +#include <support/test-driver.c> |