diff options
| -rw-r--r-- | libc/stdlib/malloc-simple/alloc.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/libc/stdlib/malloc-simple/alloc.c b/libc/stdlib/malloc-simple/alloc.c index 3baf75fdd..757a05ecf 100644 --- a/libc/stdlib/malloc-simple/alloc.c +++ b/libc/stdlib/malloc-simple/alloc.c @@ -13,6 +13,7 @@ #include <stdio.h> #include <stdlib.h> #include <string.h> +#include <stdint.h> #include <errno.h> #include <sys/mman.h> #include <malloc.h> @@ -28,6 +29,15 @@ void *malloc(size_t size) size++; } + /* prevent Undefined Behaviour for pointer arithmetic (substract) of too big pointers + * see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63303 + * No need to check for size + sizeof(size_t) integer overflow since we already check for PTRDIFF_MAX + */ + if (unlikely(size > PTRDIFF_MAX)) { + __set_errno(ENOMEM); + return 0; + } + #ifdef __ARCH_USE_MMU__ # define MMAP_FLAGS MAP_PRIVATE | MAP_ANONYMOUS #else @@ -148,6 +158,16 @@ void * memalign (size_t alignment, size_t size) void * result; unsigned long int adj; + if (unlikely(size > PTRDIFF_MAX)) { + __set_errno(ENOMEM); + return NULL; + } + + if (unlikely((size + alignment - 1 < size) && (alignment != 0))) { + __set_errno(ENOMEM); + return NULL; + } + result = malloc (size + alignment - 1); if (result == NULL) return NULL; |