glibc/malloc/tst-tcfree2.c
DJ Delorie b8dd0f4278 malloc: tcache double free check
* malloc/malloc.c (tcache_entry): Add key field.
(tcache_put): Set it.
(tcache_get): Likewise.
(_int_free): Check for double free in tcache.
* malloc/tst-tcfree1.c: New.
* malloc/tst-tcfree2.c: New.
* malloc/Makefile: Run the new tests.
* manual/probes.texi: Document memory_tcache_double_free probe.

* dlfcn/dlerror.c (check_free): Prevent double frees.

(cherry picked from commit bcdaad21d4)

malloc: tcache: Validate tc_idx before checking for double-frees [BZ #23907]

The previous check could read beyond the end of the tcache entry
array.  If the e->key == tcache cookie check happened to pass, this
would result in crashes.

(cherry picked from commit affec03b71)
2018-11-28 15:45:42 -05:00

49 lines
1.4 KiB
C

/* 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 <errno.h>
#include <error.h>
#include <limits.h>
#include <malloc.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/signal.h>
static int
do_test (void)
{
char * volatile ptrs[20];
int i;
/* Allocate enough small chunks so that when we free them all, the tcache
is full, and the first one we freed is at the end of its linked list. */
#define COUNT 20
for (i=0; i<COUNT; i++)
ptrs[i] = malloc (20);
for (i=0; i<COUNT; i++)
free (ptrs[i]);
free (ptrs[0]);
printf("FAIL: tcache double free\n");
return 1;
}
#define TEST_FUNCTION do_test
#define EXPECTED_SIGNAL SIGABRT
#include <support/test-driver.c>