From 2c21d34ea44d38835f85b90de3cbbf54abb894be Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 22 Feb 2013 20:30:52 +0100 Subject: [PATCH] avutil/mem: do a small set of checks for memalign hack before freeing. These can detect some kinds of memory and or pointer corruptions Signed-off-by: Michael Niedermayer --- libavutil/mem.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/libavutil/mem.c b/libavutil/mem.c index 250b5f745e..6d3efaabfa 100644 --- a/libavutil/mem.c +++ b/libavutil/mem.c @@ -36,6 +36,7 @@ #include #endif +#include "avassert.h" #include "avutil.h" #include "intreadwrite.h" #include "mem.h" @@ -148,6 +149,7 @@ void *av_realloc(void *ptr, size_t size) if (!ptr) return av_malloc(size); diff = ((char *)ptr)[-1]; + av_assert0(diff>0 && diff<=ALIGN); ptr = realloc((char *)ptr - diff, size + diff); if (ptr) ptr = (char *)ptr + diff; @@ -177,8 +179,11 @@ void *av_realloc_f(void *ptr, size_t nelem, size_t elsize) void av_free(void *ptr) { #if CONFIG_MEMALIGN_HACK - if (ptr) - free((char *)ptr - ((char *)ptr)[-1]); + if (ptr) { + int v= ((char *)ptr)[-1]; + av_assert0(v>0 && v<=ALIGN); + free((char *)ptr - v); + } #elif HAVE_ALIGNED_MALLOC _aligned_free(ptr); #else