Index: libarchive-3.1.2/libarchive/archive_write.c
===================================================================
--- libarchive-3.1.2.orig/libarchive/archive_write.c
+++ libarchive-3.1.2/libarchive/archive_write.c
@@ -671,8 +671,13 @@ static ssize_t
 _archive_write_data(struct archive *_a, const void *buff, size_t s)
 {
 	struct archive_write *a = (struct archive_write *)_a;
+  size_t max_write = INT_MAX;
+
 	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
 	    ARCHIVE_STATE_DATA, "archive_write_data");
+  /* This catches attempts to pass negative values. */
+  if (s > max_write)
+    s = max_write;
 	archive_clear_error(&a->archive);
 	return ((a->format_write_data)(a, buff, s));
 }