prevent allocs than PTRDIFF_MAX via mremap

It's quite feasible for this to happen via MREMAP_MAYMOVE.

diff --git a/src/mman/mremap.c b/src/mman/mremap.c
index 596c45fbded8426fc0ef19e03c3de5943ae629d3..1096ace100d0d3ddd285a399f82028a864f3bc0c 100644 (file)
--- a/src/mman/mremap.c
+++ b/src/mman/mremap.c
@@ -1,5 +1,7 @@
 #include <unistd.h>
 #include <sys/mman.h>
+#include <errno.h>
+#include <stdint.h>
 #include <stdarg.h>
 #include "syscall.h"
 #include "libc.h"
@@ -8,7 +10,12 @@ void *__mremap(void *old_addr, size_t old_len, size_t new_len, int flags, ...)
 {
        va_list ap;
        void *new_addr;
-       
+
+       if (new_len >= PTRDIFF_MAX) {
+               errno = ENOMEM;
+               return MAP_FAILED;
+       }
+
        va_start(ap, flags);
        new_addr = va_arg(ap, void *);
        va_end(ap);