objdump, nm: sprintf sanitizer null destination pointer

Seen on Ubuntu 23.04 x86_64-linux using gcc-12.2 and gcc-12.3 with
CFLAGS="-m32 -g -O2 -fsanitize=address,undefined".

  CC       objdump.o
In file included from /usr/include/stdio.h:906,
                 from /home/alan/src/binutils-gdb/binutils/sysdep.h:24,
                 from /home/alan/src/binutils-gdb/binutils/objdump.c:51:
In function 'sprintf',
    inlined from 'display_utf8' at /home/alan/src/binutils-gdb/binutils/objdump.c:621:14,
    inlined from 'sanitize_string.part.0' at /home/alan/src/binutils-gdb/binutils/objdump.c:742:11:
/usr/include/bits/stdio2.h:30:10: error: null destination pointer [-Werror=format-overflow=]
   30 |   return __builtin___sprintf_chk (__s, __USE_FORTIFY_LEVEL - 1,
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   31 |                                   __glibc_objsize (__s), __fmt,
      |                                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   32 |                                   __va_arg_pack ());
      |                                   ~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

The warning is bogus of course.  xmalloc is guaranteed to return
non-NULL, but apparently this isn't seen in display_utf6.  The same
doesn't happen with -m64, maybe due to inlining differences, I haven't
investigated fully.  Easily avoided as we hardly need to use sprintf
for a single char, or a two char string.

	* objdump.c (display_utf8): Avoid bogus sprintf sanitizer warning.
	Use hex ESC to switch back to default colour.
	(sanitize_string): Comment.  Bump buffer size by one.  Fix overlong
	line.
	* nm.c (display_utf8, sanitize_string): As above.
This commit is contained in:
Alan Modra 2023-08-03 07:29:58 +09:30
parent 1720b64f73
commit 760fb390fd
2 changed files with 32 additions and 22 deletions

View File

@ -541,13 +541,14 @@ display_utf8 (const unsigned char * in, char * out, unsigned int * consumed)
case unicode_invalid:
case unicode_hex:
out += sprintf (out, "%c", unicode_display == unicode_hex ? '<' : '{');
out += sprintf (out, "0x");
*out++ = unicode_display == unicode_hex ? '<' : '{';
*out++ = '0';
*out++ = 'x';
for (j = 0; j < nchars; j++)
out += sprintf (out, "%02x", in [j]);
out += sprintf (out, "%c", unicode_display == unicode_hex ? '>' : '}');
*out++ = unicode_display == unicode_hex ? '>' : '}';
break;
case unicode_highlight:
if (isatty (1))
out += sprintf (out, "\x1B[31;47m"); /* Red. */
@ -557,7 +558,7 @@ display_utf8 (const unsigned char * in, char * out, unsigned int * consumed)
{
case 2:
out += sprintf (out, "\\u%02x%02x",
((in[0] & 0x1c) >> 2),
((in[0] & 0x1c) >> 2),
((in[0] & 0x03) << 6) | (in[1] & 0x3f));
break;
@ -579,7 +580,7 @@ display_utf8 (const unsigned char * in, char * out, unsigned int * consumed)
}
if (unicode_display == unicode_highlight && isatty (1))
out += sprintf (out, "\033[0m"); /* Default colour. */
out += sprintf (out, "\x1B[0m"); /* Default colour. */
break;
default:
@ -633,11 +634,15 @@ convert_utf8 (const char * in)
/* Copy the input, translating as needed. */
in = original;
if (buffer_len < (strlen (in) * 9))
/* For 2 char unicode, max out is 12 (colour escapes) + 6, ie. 9 per in
For hex, max out is 8 for 2 char unicode, ie. 4 per in.
3 and 4 char unicode produce less output for input. */
size_t max_needed = strlen (in) * 9 + 1;
if (buffer_len < max_needed)
{
free ((void *) buffer);
buffer_len = strlen (in) * 9;
buffer = xmalloc (buffer_len + 1);
buffer_len = max_needed;
free (buffer);
buffer = xmalloc (buffer_len);
}
out = buffer;
@ -657,8 +662,8 @@ convert_utf8 (const char * in)
{
unsigned int num_consumed;
out += display_utf8 ((const unsigned char *)(in - 1), out, & num_consumed);
in += num_consumed - 1;
out += display_utf8 ((const unsigned char *) --in, out, &num_consumed);
in += num_consumed;
}
else
*out++ = c;

View File

@ -617,11 +617,12 @@ display_utf8 (const unsigned char * in, char * out, unsigned int * consumed)
case unicode_invalid:
case unicode_hex:
out += sprintf (out, "%c", unicode_display == unicode_hex ? '<' : '{');
out += sprintf (out, "0x");
*out++ = unicode_display == unicode_hex ? '<' : '{';
*out++ = '0';
*out++ = 'x';
for (j = 0; j < nchars; j++)
out += sprintf (out, "%02x", in [j]);
out += sprintf (out, "%c", unicode_display == unicode_hex ? '>' : '}');
*out++ = unicode_display == unicode_hex ? '>' : '}';
break;
case unicode_highlight:
@ -655,7 +656,7 @@ display_utf8 (const unsigned char * in, char * out, unsigned int * consumed)
}
if (unicode_display == unicode_highlight && isatty (1))
out += sprintf (out, "\033[0m"); /* Default colour. */
out += sprintf (out, "\x1B[0m"); /* Default colour. */
break;
default:
@ -711,11 +712,15 @@ sanitize_string (const char * in)
/* Copy the input, translating as needed. */
in = original;
if (buffer_len < (strlen (in) * 9))
/* For 2 char unicode, max out is 12 (colour escapes) + 6, ie. 9 per in
For hex, max out is 8 for 2 char unicode, ie. 4 per in.
3 and 4 char unicode produce less output for input. */
size_t max_needed = strlen (in) * 9 + 1;
if (buffer_len < max_needed)
{
free ((void *) buffer);
buffer_len = strlen (in) * 9;
buffer = xmalloc (buffer_len + 1);
buffer_len = max_needed;
free (buffer);
buffer = xmalloc (buffer_len);
}
out = buffer;
@ -735,8 +740,8 @@ sanitize_string (const char * in)
{
unsigned int num_consumed;
out += display_utf8 ((const unsigned char *)(in - 1), out, & num_consumed);
in += num_consumed - 1;
out += display_utf8 ((const unsigned char *) --in, out, &num_consumed);
in += num_consumed;
}
else
*out++ = c;