Bug 24058

Created attachment 11509 [details]
binutil-objdump-memory-leaks-readelf

hi,binutils team.i found there is memory leaks in readelf.c, when used objdump. 
here is AddressSanitizer info.

./objdump   -W poc



........
==21635==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 54 byte(s) in 2 object(s) allocated from:
    #0 0x4b91a8 in __interceptor_malloc (/root/fuzz/binutils-2.31/binutils/readelf+0x4b91a8)
    #1 0x4eb374 in get_data /root/fuzz/binutils-2.31/binutils/readelf.c:425:9
    #2 0x5548f0 in get_section_contents /root/fuzz/binutils-2.31/binutils/readelf.c:13243:20
    #3 0x5548f0 in process_notes_at /root/fuzz/binutils-2.31/binutils/readelf.c:18179
    #4 0x5126a9 in process_note_sections /root/fuzz/binutils-2.31/binutils/readelf.c:18456:10
    #5 0x5126a9 in process_notes /root/fuzz/binutils-2.31/binutils/readelf.c:18492
    #6 0x5126a9 in process_object /root/fuzz/binutils-2.31/binutils/readelf.c:18850
    #7 0x4ee043 in process_file /root/fuzz/binutils-2.31/binutils/readelf.c:19259:13
    #8 0x4ee043 in main /root/fuzz/binutils-2.31/binutils/readelf.c:19318
    #9 0x7fb198cba82f in __libc_start_main /build/glibc-Cl5G7W/glibc-2.23/csu/../csu/libc-start.c:291

SUMMARY: AddressSanitizer: 54 byte(s) leaked in 2 allocation(s).


code in binutils-2.31/binutils/readelf.c:425:9
https://github.com/bminor/binutils-gdb/blob/master/binutils/readelf.c#L424


 mvar = var;
  if (mvar == NULL)
    {
      /* Check for overflow.  */
      if (nmemb < (~(bfd_size_type) 0 - 1) / size)
	/* + 1 so that we can '\0' terminate invalid string table sections.  */
	mvar = malloc ((size_t) amt + 1);

      if (mvar == NULL)
	{
	  if (reason)
	    error (_("Out of memory allocating %s bytes for %s\n"),
		   bfd_vmatoa ("u", amt), reason);
	  return NULL;
	}

      ((char *) mvar)[amt] = '\0';
    }