From bf67003b4567600ed3022a439207ac8f26454f91 Mon Sep 17 00:00:00 2001
From: Nick Clifton <nickc@redhat.com>
Date: Mon, 27 Oct 2014 18:05:37 +0000
Subject: [PATCH] This fixes more seg-faults in tools like "strings" and "objdump" when
presented with corrupt binaries.
PR binutils/17512
* elf.c (bfd_section_from_shdr): Detect and warn about ELF
binaries with a group of sections linked by the string table
indicies.
* peXXigen.c (pe_print_edata): Detect out of range rvas and
entry counts for the Export Address table, Name Pointer table
and Ordinal table.
---
bfd/elf.c | 194 +++++++++++++++++++++++++++++++++++++-------------------
bfd/peXXigen.c | 18 +++++-
3 files changed, 150 insertions(+), 67 deletions(-)
diff --git a/bfd/elf.c b/bfd/elf.c
index c8ac826..3fcf2d8 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -1578,38 +1578,67 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
Elf_Internal_Ehdr *ehdr;
const struct elf_backend_data *bed;
const char *name;
+ bfd_boolean ret = TRUE;
+ static bfd_boolean * sections_being_created = NULL;
+ static unsigned int nesting = 0;
if (shindex >= elf_numsections (abfd))
return FALSE;
+ if (++ nesting > 3)
+ {
+ /* PR17512: A corrupt ELF binary might contain a recursive group of
+ sections, each the string indicies pointing to the next in the
+ loop. Detect this here, by refusing to load a section that we are
+ already in the process of loading. We only trigger this test if
+ we have nested at least three sections deep as normal ELF binaries
+ can expect to recurse at least once. */
+
+ if (sections_being_created == NULL)
+ {
+ /* FIXME: It would be more efficient to attach this array to the bfd somehow. */
+ sections_being_created = (bfd_boolean *)
+ bfd_zalloc (abfd, elf_numsections (abfd) * sizeof (bfd_boolean));
+ }
+ if (sections_being_created [shindex])
+ {
+ (*_bfd_error_handler)
+ (_("%B: warning: loop in section dependencies detected"), abfd);
+ return FALSE;
+ }
+ sections_being_created [shindex] = TRUE;
+ }
+
hdr = elf_elfsections (abfd)[shindex];
ehdr = elf_elfheader (abfd);
name = bfd_elf_string_from_elf_section (abfd, ehdr->e_shstrndx,
hdr->sh_name);
if (name == NULL)
- return FALSE;
+ goto fail;
bed = get_elf_backend_data (abfd);
switch (hdr->sh_type)
{
case SHT_NULL:
/* Inactive section. Throw it away. */
- return TRUE;
+ goto success;
- case SHT_PROGBITS: /* Normal section with contents. */
- case SHT_NOBITS: /* .bss section. */
- case SHT_HASH: /* .hash section. */
- case SHT_NOTE: /* .note section. */
+ case SHT_PROGBITS: /* Normal section with contents. */
+ case SHT_NOBITS: /* .bss section. */
+ case SHT_HASH: /* .hash section. */
+ case SHT_NOTE: /* .note section. */
case SHT_INIT_ARRAY: /* .init_array section. */
case SHT_FINI_ARRAY: /* .fini_array section. */
case SHT_PREINIT_ARRAY: /* .preinit_array section. */
case SHT_GNU_LIBLIST: /* .gnu.liblist section. */
case SHT_GNU_HASH: /* .gnu.hash section. */
- return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ goto success;
case SHT_DYNAMIC: /* Dynamic linking information. */
if (! _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex))
- return FALSE;
+ goto fail;
+
if (hdr->sh_link > elf_numsections (abfd))
{
/* PR 10478: Accept Solaris binaries with a sh_link
@@ -1623,11 +1652,11 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
break;
/* Otherwise fall through. */
default:
- return FALSE;
+ goto fail;
}
}
else if (elf_elfsections (abfd)[hdr->sh_link] == NULL)
- return FALSE;
+ goto fail;
else if (elf_elfsections (abfd)[hdr->sh_link]->sh_type != SHT_STRTAB)
{
Elf_Internal_Shdr *dynsymhdr;
@@ -1656,24 +1685,26 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
}
}
}
- break;
+ goto success;
- case SHT_SYMTAB: /* A symbol table */
+ case SHT_SYMTAB: /* A symbol table. */
if (elf_onesymtab (abfd) == shindex)
- return TRUE;
+ goto success;
if (hdr->sh_entsize != bed->s->sizeof_sym)
- return FALSE;
+ goto fail;
+
if (hdr->sh_info * hdr->sh_entsize > hdr->sh_size)
{
if (hdr->sh_size != 0)
- return FALSE;
+ goto fail;
/* Some assemblers erroneously set sh_info to one with a
zero sh_size. ld sees this as a global symbol count
of (unsigned) -1. Fix it here. */
hdr->sh_info = 0;
- return TRUE;
+ goto success;
}
+
BFD_ASSERT (elf_onesymtab (abfd) == 0);
elf_onesymtab (abfd) = shindex;
elf_tdata (abfd)->symtab_hdr = *hdr;
@@ -1690,7 +1721,7 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
&& (abfd->flags & DYNAMIC) != 0
&& ! _bfd_elf_make_section_from_shdr (abfd, hdr, name,
shindex))
- return FALSE;
+ goto fail;
/* Go looking for SHT_SYMTAB_SHNDX too, since if there is one we
can't read symbols without that section loaded as well. It
@@ -1716,26 +1747,29 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
break;
}
if (i != shindex)
- return bfd_section_from_shdr (abfd, i);
+ ret = bfd_section_from_shdr (abfd, i);
}
- return TRUE;
+ goto success;
- case SHT_DYNSYM: /* A dynamic symbol table */
+ case SHT_DYNSYM: /* A dynamic symbol table. */
if (elf_dynsymtab (abfd) == shindex)
- return TRUE;
+ goto success;
if (hdr->sh_entsize != bed->s->sizeof_sym)
- return FALSE;
+ goto fail;
+
if (hdr->sh_info * hdr->sh_entsize > hdr->sh_size)
{
if (hdr->sh_size != 0)
- return FALSE;
+ goto fail;
+
/* Some linkers erroneously set sh_info to one with a
zero sh_size. ld sees this as a global symbol count
of (unsigned) -1. Fix it here. */
hdr->sh_info = 0;
- return TRUE;
+ goto success;
}
+
BFD_ASSERT (elf_dynsymtab (abfd) == 0);
elf_dynsymtab (abfd) = shindex;
elf_tdata (abfd)->dynsymtab_hdr = *hdr;
@@ -1744,34 +1778,38 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
/* Besides being a symbol table, we also treat this as a regular
section, so that objcopy can handle it. */
- return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ goto success;
- case SHT_SYMTAB_SHNDX: /* Symbol section indices when >64k sections */
+ case SHT_SYMTAB_SHNDX: /* Symbol section indices when >64k sections. */
if (elf_symtab_shndx (abfd) == shindex)
- return TRUE;
+ goto success;
BFD_ASSERT (elf_symtab_shndx (abfd) == 0);
elf_symtab_shndx (abfd) = shindex;
elf_tdata (abfd)->symtab_shndx_hdr = *hdr;
elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->symtab_shndx_hdr;
- return TRUE;
+ goto success;
- case SHT_STRTAB: /* A string table */
+ case SHT_STRTAB: /* A string table. */
if (hdr->bfd_section != NULL)
- return TRUE;
+ goto success;
+
if (ehdr->e_shstrndx == shindex)
{
elf_tdata (abfd)->shstrtab_hdr = *hdr;
elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->shstrtab_hdr;
- return TRUE;
+ goto success;
}
+
if (elf_elfsections (abfd)[elf_onesymtab (abfd)]->sh_link == shindex)
{
symtab_strtab:
elf_tdata (abfd)->strtab_hdr = *hdr;
elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->strtab_hdr;
- return TRUE;
+ goto success;
}
+
if (elf_elfsections (abfd)[elf_dynsymtab (abfd)]->sh_link == shindex)
{
dynsymtab_strtab:
@@ -1780,8 +1818,9 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
elf_elfsections (abfd)[shindex] = hdr;
/* We also treat this as a regular section, so that objcopy
can handle it. */
- return _bfd_elf_make_section_from_shdr (abfd, hdr, name,
- shindex);
+ ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name,
+ shindex);
+ goto success;
}
/* If the string table isn't one of the above, then treat it as a
@@ -1799,9 +1838,9 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
{
/* Prevent endless recursion on broken objects. */
if (i == shindex)
- return FALSE;
+ goto fail;
if (! bfd_section_from_shdr (abfd, i))
- return FALSE;
+ goto fail;
if (elf_onesymtab (abfd) == i)
goto symtab_strtab;
if (elf_dynsymtab (abfd) == i)
@@ -1809,7 +1848,8 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
}
}
}
- return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ goto success;
case SHT_REL:
case SHT_RELA:
@@ -1824,7 +1864,7 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
if (hdr->sh_entsize
!= (bfd_size_type) (hdr->sh_type == SHT_REL
? bed->s->sizeof_rel : bed->s->sizeof_rela))
- return FALSE;
+ goto fail;
/* Check for a bogus link to avoid crashing. */
if (hdr->sh_link >= num_sec)
@@ -1832,8 +1872,9 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
((*_bfd_error_handler)
(_("%B: invalid link %lu for reloc section %s (index %u)"),
abfd, hdr->sh_link, name, shindex));
- return _bfd_elf_make_section_from_shdr (abfd, hdr, name,
- shindex);
+ ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name,
+ shindex);
+ goto success;
}
/* For some incomprehensible reason Oracle distributes
@@ -1874,7 +1915,7 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
if ((elf_elfsections (abfd)[hdr->sh_link]->sh_type == SHT_SYMTAB
|| elf_elfsections (abfd)[hdr->sh_link]->sh_type == SHT_DYNSYM)
&& ! bfd_section_from_shdr (abfd, hdr->sh_link))
- return FALSE;
+ goto fail;
/* If this reloc section does not use the main symbol table we
don't treat it as a reloc section. BFD can't adequately
@@ -1889,14 +1930,18 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
|| hdr->sh_info >= num_sec
|| elf_elfsections (abfd)[hdr->sh_info]->sh_type == SHT_REL
|| elf_elfsections (abfd)[hdr->sh_info]->sh_type == SHT_RELA)
- return _bfd_elf_make_section_from_shdr (abfd, hdr, name,
- shindex);
+ {
+ ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name,
+ shindex);
+ goto success;
+ }
if (! bfd_section_from_shdr (abfd, hdr->sh_info))
- return FALSE;
+ goto fail;
+
target_sect = bfd_section_from_elf_index (abfd, hdr->sh_info);
if (target_sect == NULL)
- return FALSE;
+ goto fail;
esdt = elf_section_data (target_sect);
if (hdr->sh_type == SHT_RELA)
@@ -1908,7 +1953,7 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
amt = sizeof (*hdr2);
hdr2 = (Elf_Internal_Shdr *) bfd_alloc (abfd, amt);
if (hdr2 == NULL)
- return FALSE;
+ goto fail;
*hdr2 = *hdr;
*p_hdr = hdr2;
elf_elfsections (abfd)[shindex] = hdr2;
@@ -1924,34 +1969,40 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
target_sect->use_rela_p = 1;
}
abfd->flags |= HAS_RELOC;
- return TRUE;
+ goto success;
}
case SHT_GNU_verdef:
elf_dynverdef (abfd) = shindex;
elf_tdata (abfd)->dynverdef_hdr = *hdr;
- return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ goto success;
case SHT_GNU_versym:
if (hdr->sh_entsize != sizeof (Elf_External_Versym))
- return FALSE;
+ goto fail;
+
elf_dynversym (abfd) = shindex;
elf_tdata (abfd)->dynversym_hdr = *hdr;
- return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ goto success;
case SHT_GNU_verneed:
elf_dynverref (abfd) = shindex;
elf_tdata (abfd)->dynverref_hdr = *hdr;
- return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ goto success;
case SHT_SHLIB:
- return TRUE;
+ goto success;
case SHT_GROUP:
if (! IS_VALID_GROUP_SECTION_HEADER (hdr, GRP_ENTRY_SIZE))
- return FALSE;
+ goto fail;
+
if (!_bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex))
- return FALSE;
+ goto fail;
+
if (hdr->contents != NULL)
{
Elf_Internal_Group *idx = (Elf_Internal_Group *) hdr->contents;
@@ -1977,7 +2028,7 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
}
}
}
- break;
+ goto success;
default:
/* Possibly an attributes section. */
@@ -1985,14 +2036,14 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
|| hdr->sh_type == bed->obj_attrs_section_type)
{
if (! _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex))
- return FALSE;
+ goto fail;
_bfd_elf_parse_attributes (abfd, hdr);
- return TRUE;
+ goto success;
}
/* Check for any processor-specific section types. */
if (bed->elf_backend_section_from_shdr (abfd, hdr, name, shindex))
- return TRUE;
+ goto success;
if (hdr->sh_type >= SHT_LOUSER && hdr->sh_type <= SHT_HIUSER)
{
@@ -2004,9 +2055,12 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
"specific section `%s' [0x%8x]"),
abfd, name, hdr->sh_type);
else
- /* Allow sections reserved for applications. */
- return _bfd_elf_make_section_from_shdr (abfd, hdr, name,
- shindex);
+ {
+ /* Allow sections reserved for applications. */
+ ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name,
+ shindex);
+ goto success;
+ }
}
else if (hdr->sh_type >= SHT_LOPROC
&& hdr->sh_type <= SHT_HIPROC)
@@ -2027,8 +2081,11 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
"`%s' [0x%8x]"),
abfd, name, hdr->sh_type);
else
- /* Otherwise it should be processed. */
- return _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ {
+ /* Otherwise it should be processed. */
+ ret = _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex);
+ goto success;
+ }
}
else
/* FIXME: We should handle this section. */
@@ -2036,10 +2093,17 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
(_("%B: don't know how to handle section `%s' [0x%8x]"),
abfd, name, hdr->sh_type);
- return FALSE;
+ goto fail;
}
- return TRUE;
+ fail:
+ ret = FALSE;
+ success:
+ if (sections_being_created)
+ sections_being_created [shindex] = FALSE;
+ if (-- nesting == 0)
+ sections_being_created = NULL;
+ return ret;
}
/* Return the local symbol specified by ABFD, R_SYMNDX. */
diff --git a/bfd/peXXigen.c b/bfd/peXXigen.c
index 987be40..c7d6067 100644
--- a/bfd/peXXigen.c
+++ b/bfd/peXXigen.c
@@ -1705,7 +1705,12 @@ pe_print_edata (bfd * abfd, void * vfile)
_("\nExport Address Table -- Ordinal Base %ld\n"),
edt.base);
- for (i = 0; i < edt.num_functions; ++i)
+ /* PR 17512: Handle corrupt PE binaries. */
+ if (edt.eat_addr + (edt.num_functions * 4) - adj >= datasize)
+ fprintf (file, _("\tInvalid Export Address Table rva (0x%lx) or entry count (0x%lx)\n"),
+ (long) edt.eat_addr,
+ (long) edt.num_functions);
+ else for (i = 0; i < edt.num_functions; ++i)
{
bfd_vma eat_member = bfd_get_32 (abfd,
data + edt.eat_addr + (i * 4) - adj);
@@ -1741,7 +1746,16 @@ pe_print_edata (bfd * abfd, void * vfile)
fprintf (file,
_("\n[Ordinal/Name Pointer] Table\n"));
- for (i = 0; i < edt.num_names; ++i)
+ /* PR 17512: Handle corrupt PE binaries. */
+ if (edt.npt_addr + (edt.num_names * 4) - adj >= datasize)
+ fprintf (file, _("\tInvalid Name Pointer Table rva (0x%lx) or entry count (0x%lx)\n"),
+ (long) edt.npt_addr,
+ (long) edt.num_names);
+ else if (edt.ot_addr + (edt.num_names * 2) - adj >= datasize)
+ fprintf (file, _("\tInvalid Ordinal Table rva (0x%lx) or entry count (0x%lx)\n"),
+ (long) edt.ot_addr,
+ (long) edt.num_names);
+ else for (i = 0; i < edt.num_names; ++i)
{
bfd_vma name_ptr = bfd_get_32 (abfd,
data +
--
1.7.1