Re: [PATCH 2/2] [nto] Improve ABI sniffing.

[Pedro Alves <palves@redhat.com>]

On 10/21/2015 02:34 PM, Aleksandar Ristovski wrote:

> +static void
> +nto_sniff_abi_note_section (bfd *abfd, asection *sect, void *obj)
> +{
> +  const char *sectname;
> +  unsigned int sectsize;
> +  /* Buffer holding the section contents.  */
> +  char *note;
> +  unsigned int namelen;
> +  const char *name;
> +
> +  sectname = bfd_get_section_name (abfd, sect);
> +  sectsize = bfd_section_size (abfd, sect);
> +
> +  if (sectsize > 128)
> +    sectsize = 128;
> +
> +  if (sectname != NULL && strstr (sectname, QNX_INFO_SECT_NAME) != NULL)
> +    *(enum gdb_osabi *) obj = GDB_OSABI_QNXNTO;
> +
> +  if (sectname != NULL && strstr (sectname, "note") != NULL)

This can be "else if".

> +    {
> +      const unsigned sizeof_Elf_Nhdr = 12;
> +
> +      note = XNEWVEC (char, sectsize);
> +      bfd_get_section_contents (abfd, sect, note, 0, sectsize);
> +      namelen = (unsigned int) bfd_h_get_32 (abfd, note);

You also need to check that the section's size
is enough to contain 'namelen', _before_ extracting it, otherwise
you may be reading garbage.


> +      name = note + sizeof_Elf_Nhdr;
> +      if (sectsize < namelen + sizeof_Elf_Nhdr

> +	  || namelen > sizeof (QNX_NOTE_NAME) + 1)
> +	{
> +	  /* Can not be QNX note.  */
> +	  XDELETEVEC (note);
> +	  return;

Thanks,
Pedro Alves