[libbacktrace] Don't point to released memory in backtrace_vector_release

When backtrace_vector_release is called with vec.size == 0, it releases the
memory pointed at by vec.base.

Set vec.base set to NULL if vec.size == 0 to ensure we don't point to released
memory.

Bootstrapped and reg-tested on x86_64.

2018-11-27  Tom de Vries  <tdevries@suse.de>

	* mmap.c (backtrace_vector_release): Same.
	* unittest.c (test1): Add check.

From-SVN: r266505
This commit is contained in:
Tom de Vries 2018-11-27 08:26:04 +00:00 committed by Tom de Vries
parent 0c155f24a9
commit 6d760a0197
3 changed files with 8 additions and 1 deletions

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@ -1,3 +1,8 @@
2018-11-27 Tom de Vries <tdevries@suse.de>
* mmap.c (backtrace_vector_release): Same.
* unittest.c (test1): Add check.
2018-11-27 Tom de Vries <tdevries@suse.de>
* alloc.c (backtrace_vector_release): Handle vec->size == 0 using free

View File

@ -321,5 +321,7 @@ backtrace_vector_release (struct backtrace_state *state,
backtrace_free (state, (char *) vec->base + aligned, alc,
error_callback, data);
vec->alc = 0;
if (vec->size == 0)
vec->base = NULL;
return 1;
}

View File

@ -69,7 +69,7 @@ test1 (void)
count = 0;
res = backtrace_vector_release (state, &vec, error_callback, NULL);
failed = res != 1 || count != 0;
failed = res != 1 || count != 0 || vec.base != NULL;
printf ("%s: unittest backtrace_vector_release size == 0\n",
failed ? "FAIL": "PASS");