From: Mark Wooding <mdw@distorted.org.uk>
Date: Fri, 11 Oct 2019 22:15:42 +0000 (+0100)
Subject: struct/buf.c (buf_getmem*): Add an explicit `BENSURE'.
X-Git-Tag: 2.4.2~2
X-Git-Url: https://git.distorted.org.uk/~mdw/mLib/commitdiff_plain/f868c4327d366a7e142e27ffbaa383d75aef6c1b

struct/buf.c (buf_getmem*): Add an explicit `BENSURE'.

Otherwise we fail when processing a 64-bit length on a 32-bit platform:
an overlong 64-bit length gets truncated to a possibly-acceptable 32-bit
length in the implicit conversion to `size_t' in the call to `buf_get'.
Using `BENSURE' directly ensures that the comparison gets done with the
correct integer type.
---

diff --git a/struct/buf.c b/struct/buf.c
index d86904c..bd16ec7 100644
--- a/struct/buf.c
+++ b/struct/buf.c
@@ -247,6 +247,7 @@ static int findz(buf *b, size_t *nn)
   {									\
     uint##n sz;								\
     if (buf_getu##w(b, &sz)) return (0);				\
+    if (BENSURE(b, sz)) return (0);					\
     *nn = sz;								\
     return (buf_get(b, sz));						\
   }