Avoid allocating over-large buffers when parsing corrupt binaries.

PR binutils/17512
	* coffgen.c (_bfd_coff_get_external_symbols): Do not try to load a
	symbol table bigger than the file.
	* elf.c (bfd_elf_get_str_section): Do not try to load a string
	table bigger than the file.

	* readelf.c (process_program_headers): Avoid memory exhaustion due
	to corrupt values in a dynamis segment header.
	(get_32bit_elf_symbols): Do not attempt to read an over-large
	section.
	(get_64bit_elf_symbols): Likewise.
This commit is contained in:
Nick Clifton 2014-10-31 16:36:31 +00:00
parent fe06005387
commit f54498b457
5 changed files with 55 additions and 4 deletions

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@ -1,3 +1,11 @@
2014-10-31 Nick Clifton <nickc@redhat.com>
PR binutils/17512
* coffgen.c (_bfd_coff_get_external_symbols): Do not try to load a
symbol table bigger than the file.
* elf.c (bfd_elf_get_str_section): Do not try to load a string
table bigger than the file.
2014-10-30 Nick Clifton <nickc@redhat.com>
PR binutils/17512

View File

@ -1616,6 +1616,11 @@ _bfd_coff_get_external_symbols (bfd *abfd)
if (size == 0)
return TRUE;
/* PR binutils/17512: Do not even try to load
a symbol table bigger than the entire file... */
if (size >= (bfd_size_type) bfd_get_size (abfd))
return FALSE;
syms = bfd_malloc (size);
if (syms == NULL)
return FALSE;

View File

@ -294,6 +294,11 @@ bfd_elf_get_str_section (bfd *abfd, unsigned int shindex)
offset = i_shdrp[shindex]->sh_offset;
shstrtabsize = i_shdrp[shindex]->sh_size;
/* PR binutils/17512: Do not even try to load
a string table bigger than the entire file... */
if (shstrtabsize >= (bfd_size_type) bfd_get_size (abfd))
return NULL;
/* Allocate and clear an extra byte at the end, to prevent crashes
in case the string table is not terminated. */
if (shstrtabsize + 1 <= 1

View File

@ -1,3 +1,12 @@
2014-10-31 Nick Clifton <nickc@redhat.com>
PR binutils/17512
* readelf.c (process_program_headers): Avoid memory exhaustion due
to corrupt values in a dynamis segment header.
(get_32bit_elf_symbols): Do not attempt to read an over-large
section.
(get_64bit_elf_symbols): Likewise.
2014-10-31 Nick Clifton <nickc@redhat.com>
* strings.c: Add new command line option --data to only scan the

View File

@ -167,6 +167,7 @@
char * program_name = "readelf";
static long archive_file_offset;
static unsigned long archive_file_size;
static bfd_size_type current_file_size;
static unsigned long dynamic_addr;
static bfd_size_type dynamic_size;
static unsigned int dynamic_nent;
@ -4341,6 +4342,9 @@ process_program_headers (FILE * file)
}
}
if (do_segments)
putc ('\n', stdout);
switch (segment->p_type)
{
case PT_DYNAMIC:
@ -4351,6 +4355,12 @@ process_program_headers (FILE * file)
section in the DYNAMIC segment. */
dynamic_addr = segment->p_offset;
dynamic_size = segment->p_filesz;
/* PR binutils/17512: Avoid corrupt dynamic section info in the segment. */
if (dynamic_addr + dynamic_size >= current_file_size)
{
error (_("the dynamic segment offset + size exceeds the size of the file\n"));
dynamic_addr = dynamic_size = 0;
}
/* Try to locate the .dynamic section. If there is
a section header table, we can easily locate it. */
@ -4404,14 +4414,11 @@ process_program_headers (FILE * file)
error (_("Unable to read program interpreter name\n"));
if (do_segments)
printf (_("\n [Requesting program interpreter: %s]"),
printf (_(" [Requesting program interpreter: %s]\n"),
program_interpreter);
}
break;
}
if (do_segments)
putc ('\n', stdout);
}
if (do_segments && section_headers != NULL && string_table != NULL)
@ -4580,6 +4587,13 @@ get_32bit_elf_symbols (FILE * file,
goto exit_point;
}
if (section->sh_size > current_file_size)
{
error (_("Section %s has an invalid sh_size of 0x%lx\n"),
SECTION_NAME (section), section->sh_size);
goto exit_point;
}
number = section->sh_size / section->sh_entsize;
if (number * sizeof (Elf32_External_Sym) > section->sh_size + 1)
@ -4660,6 +4674,13 @@ get_64bit_elf_symbols (FILE * file,
goto exit_point;
}
if (section->sh_size > current_file_size)
{
error (_("Section %s has an invalid sh_size of 0x%lx\n"),
SECTION_NAME (section), section->sh_size);
goto exit_point;
}
number = section->sh_size / section->sh_entsize;
if (number * sizeof (Elf64_External_Sym) > section->sh_size + 1)
@ -14886,6 +14907,8 @@ process_file (char * file_name)
return 1;
}
current_file_size = (bfd_size_type) statbuf.st_size;
if (memcmp (armag, ARMAG, SARMAG) == 0)
ret = process_archive (file_name, file, FALSE);
else if (memcmp (armag, ARMAGT, SARMAG) == 0)
@ -14903,6 +14926,7 @@ process_file (char * file_name)
fclose (file);
current_file_size = 0;
return ret;
}