From a2daa89be5647e6c51c899e511604bfa53d1e318 Mon Sep 17 00:00:00 2001
From: Igor Malovitsa <igor.malovitsa@gmail.com>
Date: Wed, 6 Mar 2024 21:05:21 +0200
Subject: [PATCH] more oob checks

---
 hbas.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/hbas.c b/hbas.c
index f36909a..2e876d6 100644
--- a/hbas.c
+++ b/hbas.c
@@ -351,7 +351,13 @@ typedef struct ByteVec_s {
 } ByteVec;
 
 AsmError ensure_push(ByteVec *vec, size_t el_size, size_t extra) {
+    if (vec->len + extra < vec->len) {
+        return ErrOutOfMemory;
+    }
     while (vec->len + extra > vec->cap) {
+        if ((~(size_t)0) / 2 < vec->cap) {
+            return ErrOutOfMemory;
+        }
         vec->cap *= 2;
         // multiply overflow
         if ((~(size_t)0) / el_size < vec->cap) {
@@ -705,11 +711,11 @@ AsmError assemble_instr(
             }
             // num_to_write = num_to_write ^ is_negative - is_negative;
             if (is_negative) {
-                int64_t tmp = (int64_t)num_to_write;
-                if (tmp < 0) {
+                int64_t tmp = -(int64_t)num_to_write;
+                if (tmp > 0) {
                     return ErrBadNumOverflow;
                 }
-                num_to_write = (uint64_t)(-tmp);
+                num_to_write = (uint64_t)tmp;
             }
             AsmError err = push_int_le(
                 &rv->buf[rv->len], num_to_write, meta.size, meta.sign