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bug#13827: faulty range check in bytevector accessor
From: |
Andy Wingo |
Subject: |
bug#13827: faulty range check in bytevector accessor |
Date: |
Wed, 13 Mar 2013 13:55:14 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/24.2 (gnu/linux) |
On Wed 27 Feb 2013 03:02, Ian Price <address@hidden> writes:
> Branch: master
> Commit: 9b977c836bf147d386944c401113aba32776fa68
> System: 32 bit x86 Fedora 16
>
> (use-modules (rnrs bytevectors))
> (define not-32-bit (expt 2 32))
> (define bv (make-bytevector 4))
> (bytevector-u32-set! bv 0 not-32-bit (endianness big))
> (pk bv)
>
> Running this gives me a core dump. It happens for a wide range of values
> that don't fit in 32 bits.
>
> After some talk on #guile, Mark and I believe it comes down to the range
> check in INTEGER_ACCESSOR_PROLOGUE in bytevectors.c
Something like this look right to you?
--- a/libguile/bytevectors.c
+++ b/libguile/bytevectors.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
+/* Copyright (C) 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
@@ -82,12 +82,12 @@
_sign char *c_bv; \
\
SCM_VALIDATE_BYTEVECTOR (1, bv); \
- c_index = scm_to_uint (index); \
+ c_index = scm_to_size_t (index); \
\
c_len = SCM_BYTEVECTOR_LENGTH (bv); \
c_bv = (_sign char *) SCM_BYTEVECTOR_CONTENTS (bv); \
\
- if (SCM_UNLIKELY (c_index + ((_len) >> 3UL) - 1 >= c_len)) \
+ if (SCM_UNLIKELY (c_index >= c_len)) \
scm_out_of_range (FUNC_NAME, index);
/* Template for fixed-size integer access (only 8, 16 or 32-bit). */
--
http://wingolog.org/
- bug#13827: faulty range check in bytevector accessor,
Andy Wingo <=