From 6d760a0197ece131619ac88f0fe34ce452fd774c Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Tue, 27 Nov 2018 08:26:04 +0000 Subject: [PATCH] [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 * mmap.c (backtrace_vector_release): Same. * unittest.c (test1): Add check. From-SVN: r266505 --- libbacktrace/ChangeLog | 5 +++++ libbacktrace/mmap.c | 2 ++ libbacktrace/unittest.c | 2 +- 3 files changed, 8 insertions(+), 1 deletion(-) diff --git a/libbacktrace/ChangeLog b/libbacktrace/ChangeLog index 255e2c8921e..e7fdfd8e940 100644 --- a/libbacktrace/ChangeLog +++ b/libbacktrace/ChangeLog @@ -1,3 +1,8 @@ +2018-11-27 Tom de Vries + + * mmap.c (backtrace_vector_release): Same. + * unittest.c (test1): Add check. + 2018-11-27 Tom de Vries * alloc.c (backtrace_vector_release): Handle vec->size == 0 using free diff --git a/libbacktrace/mmap.c b/libbacktrace/mmap.c index 32fcba62399..9f896a1bb99 100644 --- a/libbacktrace/mmap.c +++ b/libbacktrace/mmap.c @@ -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; } diff --git a/libbacktrace/unittest.c b/libbacktrace/unittest.c index 576aa080935..3471d78488d 100644 --- a/libbacktrace/unittest.c +++ b/libbacktrace/unittest.c @@ -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");