readelf section reading
This is a followup to git commit 8ff66993e0, a patch aimed at
segfaults found invoking readelf multiple times with fuzzed objects.
In that patch I added code to clear more stashed data early in
process_section_headers, along with any stashed section headers. This
patch instead relies on clearing out the stash at the end of
process_object, making sure that process_object doesn't exit early.
The patch also introduces some new wrapper functions.
* readelf.c (GET_ELF_SYMBOLS): Delete. Replace with..
(get_elf_symbols): ..this new function throughout.
(get_32bit_section_headers): Don't free section_headers.
(get_64bit_section_headers): Likewise.
(get_section_headers): New function, use throughout in place of
32bit and 64bit variants.
(get_dynamic_section): Similarly.
(process_section_headers): Don't free filedata memory here.
(get_file_header): Don't get section headers here..
(process_object): ..Read them here instead. Don't exit without
freeing filedata memory.
This commit is contained in:
Alan Modra
parent
f64b9b13ce
commit
4de91c10cd
2 changed files with 74 additions and 74 deletions
|
|
@ -1,3 +1,17 @@
|
|||
2021-06-11 Alan Modra <amodra@gmail.com>
|
||||
|
||||
* readelf.c (GET_ELF_SYMBOLS): Delete. Replace with..
|
||||
(get_elf_symbols): ..this new function throughout.
|
||||
(get_32bit_section_headers): Don't free section_headers.
|
||||
(get_64bit_section_headers): Likewise.
|
||||
(get_section_headers): New function, use throughout in place of
|
||||
32bit and 64bit variants.
|
||||
(get_dynamic_section): Similarly.
|
||||
(process_section_headers): Don't free filedata memory here.
|
||||
(get_file_header): Don't get section headers here..
|
||||
(process_object): ..Read them here instead. Don't exit without
|
||||
freeing filedata memory.
|
||||
|
||||
2021-06-09 Nick Clifton <nickc@redhat.com>
|
||||
|
||||
* MAINTAINERS: Remove Daniel Jacobwitz from the maintainers list.
|
||||
|
|
|
|||
|
|
@ -357,10 +357,6 @@ static const char * get_symbol_version_string
|
|||
|
||||
#define DT_VERSIONTAGIDX(tag) (DT_VERNEEDNUM - (tag)) /* Reverse order! */
|
||||
|
||||
#define GET_ELF_SYMBOLS(file, section, sym_count) \
|
||||
(is_32bit_elf ? get_32bit_elf_symbols (file, section, sym_count) \
|
||||
: get_64bit_elf_symbols (file, section, sym_count))
|
||||
|
||||
#define VALID_SYMBOL_NAME(strtab, strtab_size, offset) \
|
||||
(strtab != NULL && offset < strtab_size)
|
||||
#define VALID_DYNAMIC_NAME(filedata, offset) \
|
||||
|
|
@ -5756,7 +5752,6 @@ get_32bit_section_headers (Filedata * filedata, bool probe)
|
|||
if (shdrs == NULL)
|
||||
return false;
|
||||
|
||||
free (filedata->section_headers);
|
||||
filedata->section_headers = (Elf_Internal_Shdr *)
|
||||
cmalloc (num, sizeof (Elf_Internal_Shdr));
|
||||
if (filedata->section_headers == NULL)
|
||||
|
|
@ -5823,7 +5818,6 @@ get_64bit_section_headers (Filedata * filedata, bool probe)
|
|||
if (shdrs == NULL)
|
||||
return false;
|
||||
|
||||
free (filedata->section_headers);
|
||||
filedata->section_headers = (Elf_Internal_Shdr *)
|
||||
cmalloc (num, sizeof (Elf_Internal_Shdr));
|
||||
if (filedata->section_headers == NULL)
|
||||
|
|
@ -5858,6 +5852,21 @@ get_64bit_section_headers (Filedata * filedata, bool probe)
|
|||
return true;
|
||||
}
|
||||
|
||||
static bool
|
||||
get_section_headers (Filedata *filedata, bool probe)
|
||||
{
|
||||
if (filedata->section_headers != NULL)
|
||||
return true;
|
||||
|
||||
if (filedata->file_header.e_shoff == 0)
|
||||
return true;
|
||||
|
||||
if (is_32bit_elf)
|
||||
return get_32bit_section_headers (filedata, probe);
|
||||
else
|
||||
return get_64bit_section_headers (filedata, probe);
|
||||
}
|
||||
|
||||
static Elf_Internal_Sym *
|
||||
get_32bit_elf_symbols (Filedata * filedata,
|
||||
Elf_Internal_Shdr * section,
|
||||
|
|
@ -6094,6 +6103,17 @@ get_64bit_elf_symbols (Filedata * filedata,
|
|||
return isyms;
|
||||
}
|
||||
|
||||
static Elf_Internal_Sym *
|
||||
get_elf_symbols (Filedata *filedata,
|
||||
Elf_Internal_Shdr *section,
|
||||
unsigned long *num_syms_return)
|
||||
{
|
||||
if (is_32bit_elf)
|
||||
return get_32bit_elf_symbols (filedata, section, num_syms_return);
|
||||
else
|
||||
return get_64bit_elf_symbols (filedata, section, num_syms_return);
|
||||
}
|
||||
|
||||
static const char *
|
||||
get_elf_section_flags (Filedata * filedata, bfd_vma sh_flags)
|
||||
{
|
||||
|
|
@ -6451,23 +6471,6 @@ process_section_headers (Filedata * filedata)
|
|||
Elf_Internal_Shdr * section;
|
||||
unsigned int i;
|
||||
|
||||
free (filedata->section_headers);
|
||||
filedata->section_headers = NULL;
|
||||
free (filedata->dynamic_symbols);
|
||||
filedata->dynamic_symbols = NULL;
|
||||
filedata->num_dynamic_syms = 0;
|
||||
free (filedata->dynamic_strings);
|
||||
filedata->dynamic_strings = NULL;
|
||||
filedata->dynamic_strings_length = 0;
|
||||
free (filedata->dynamic_syminfo);
|
||||
filedata->dynamic_syminfo = NULL;
|
||||
while (filedata->symtab_shndx_list != NULL)
|
||||
{
|
||||
elf_section_list *next = filedata->symtab_shndx_list->next;
|
||||
free (filedata->symtab_shndx_list);
|
||||
filedata->symtab_shndx_list = next;
|
||||
}
|
||||
|
||||
if (filedata->file_header.e_shnum == 0)
|
||||
{
|
||||
/* PR binutils/12467. */
|
||||
|
|
@ -6497,16 +6500,8 @@ process_section_headers (Filedata * filedata)
|
|||
(unsigned long) filedata->file_header.e_shoff);
|
||||
}
|
||||
|
||||
if (is_32bit_elf)
|
||||
{
|
||||
if (! get_32bit_section_headers (filedata, false))
|
||||
return false;
|
||||
}
|
||||
else
|
||||
{
|
||||
if (! get_64bit_section_headers (filedata, false))
|
||||
return false;
|
||||
}
|
||||
if (!get_section_headers (filedata, false))
|
||||
return false;
|
||||
|
||||
/* Read in the string table, so that we have names to display. */
|
||||
if (filedata->file_header.e_shstrndx != SHN_UNDEF
|
||||
|
|
@ -6615,7 +6610,7 @@ process_section_headers (Filedata * filedata)
|
|||
|
||||
CHECK_ENTSIZE (section, i, Sym);
|
||||
filedata->dynamic_symbols
|
||||
= GET_ELF_SYMBOLS (filedata, section, &filedata->num_dynamic_syms);
|
||||
= get_elf_symbols (filedata, section, &filedata->num_dynamic_syms);
|
||||
filedata->dynamic_symtab_section = section;
|
||||
break;
|
||||
|
||||
|
|
@ -7170,7 +7165,7 @@ get_symtab (Filedata *filedata, Elf_Internal_Shdr *symsec,
|
|||
{
|
||||
*strtab = NULL;
|
||||
*strtablen = 0;
|
||||
*symtab = GET_ELF_SYMBOLS (filedata, symsec, nsyms);
|
||||
*symtab = get_elf_symbols (filedata, symsec, nsyms);
|
||||
|
||||
if (*symtab == NULL)
|
||||
return false;
|
||||
|
|
@ -7341,7 +7336,7 @@ process_section_groups (Filedata * filedata)
|
|||
{
|
||||
symtab_sec = sec;
|
||||
free (symtab);
|
||||
symtab = GET_ELF_SYMBOLS (filedata, symtab_sec, & num_syms);
|
||||
symtab = get_elf_symbols (filedata, symtab_sec, & num_syms);
|
||||
}
|
||||
|
||||
if (symtab == NULL)
|
||||
|
|
@ -10278,6 +10273,18 @@ get_64bit_dynamic_section (Filedata * filedata)
|
|||
return true;
|
||||
}
|
||||
|
||||
static bool
|
||||
get_dynamic_section (Filedata *filedata)
|
||||
{
|
||||
if (filedata->dynamic_section)
|
||||
return true;
|
||||
|
||||
if (is_32bit_elf)
|
||||
return get_32bit_dynamic_section (filedata);
|
||||
else
|
||||
return get_64bit_dynamic_section (filedata);
|
||||
}
|
||||
|
||||
static void
|
||||
print_dynamic_flags (bfd_vma flags)
|
||||
{
|
||||
|
|
@ -10621,16 +10628,8 @@ process_dynamic_section (Filedata * filedata)
|
|||
return true;
|
||||
}
|
||||
|
||||
if (is_32bit_elf)
|
||||
{
|
||||
if (! get_32bit_dynamic_section (filedata))
|
||||
return false;
|
||||
}
|
||||
else
|
||||
{
|
||||
if (! get_64bit_dynamic_section (filedata))
|
||||
return false;
|
||||
}
|
||||
if (!get_dynamic_section (filedata))
|
||||
return false;
|
||||
|
||||
/* Find the appropriate symbol table. */
|
||||
if (filedata->dynamic_symbols == NULL || do_histogram)
|
||||
|
|
@ -10714,7 +10713,7 @@ the .dynsym section doesn't match the DT_SYMTAB and DT_SYMENT tags\n"));
|
|||
|
||||
section.sh_name = filedata->string_table_length;
|
||||
filedata->dynamic_symbols
|
||||
= GET_ELF_SYMBOLS (filedata, §ion,
|
||||
= get_elf_symbols (filedata, §ion,
|
||||
&filedata->num_dynamic_syms);
|
||||
if (filedata->dynamic_symbols == NULL
|
||||
|| filedata->num_dynamic_syms != num_of_syms)
|
||||
|
|
@ -11744,7 +11743,7 @@ process_version_sections (Filedata * filedata)
|
|||
|
||||
found = true;
|
||||
|
||||
symbols = GET_ELF_SYMBOLS (filedata, link_section, & num_syms);
|
||||
symbols = get_elf_symbols (filedata, link_section, & num_syms);
|
||||
if (symbols == NULL)
|
||||
break;
|
||||
|
||||
|
|
@ -12946,7 +12945,7 @@ process_symbol_table (Filedata * filedata)
|
|||
else
|
||||
printf (_(" Num: Value Size Type Bind Vis Ndx Name\n"));
|
||||
|
||||
symtab = GET_ELF_SYMBOLS (filedata, section, & num_syms);
|
||||
symtab = get_elf_symbols (filedata, section, & num_syms);
|
||||
if (symtab == NULL)
|
||||
continue;
|
||||
|
||||
|
|
@ -14312,7 +14311,7 @@ apply_relocations (Filedata * filedata,
|
|||
if (filedata->file_header.e_machine == EM_SH)
|
||||
is_rela = false;
|
||||
|
||||
symtab = GET_ELF_SYMBOLS (filedata, symsec, & num_syms);
|
||||
symtab = get_elf_symbols (filedata, symsec, & num_syms);
|
||||
|
||||
for (rp = relocs; rp < relocs + num_relocs; ++rp)
|
||||
{
|
||||
|
|
@ -21185,16 +21184,6 @@ get_file_header (Filedata * filedata)
|
|||
filedata->file_header.e_shstrndx = BYTE_GET (ehdr64.e_shstrndx);
|
||||
}
|
||||
|
||||
if (filedata->file_header.e_shoff)
|
||||
{
|
||||
/* There may be some extensions in the first section header. Don't
|
||||
bomb if we can't read it. */
|
||||
if (is_32bit_elf)
|
||||
get_32bit_section_headers (filedata, true);
|
||||
else
|
||||
get_64bit_section_headers (filedata, true);
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
|
|
@ -21305,19 +21294,8 @@ open_file (const char * pathname, bool is_separate)
|
|||
if (! get_file_header (filedata))
|
||||
goto fail;
|
||||
|
||||
if (filedata->file_header.e_shoff)
|
||||
{
|
||||
bool res;
|
||||
|
||||
/* Read the section headers again, this time for real. */
|
||||
if (is_32bit_elf)
|
||||
res = get_32bit_section_headers (filedata, false);
|
||||
else
|
||||
res = get_64bit_section_headers (filedata, false);
|
||||
|
||||
if (!res)
|
||||
goto fail;
|
||||
}
|
||||
if (!get_section_headers (filedata, false))
|
||||
goto fail;
|
||||
|
||||
return filedata;
|
||||
|
||||
|
|
@ -21393,8 +21371,15 @@ process_object (Filedata * filedata)
|
|||
|
||||
initialise_dump_sects (filedata);
|
||||
|
||||
/* There may be some extensions in the first section header. Don't
|
||||
bomb if we can't read it. */
|
||||
get_section_headers (filedata, true);
|
||||
|
||||
if (! process_file_header (filedata))
|
||||
return false;
|
||||
{
|
||||
res = false;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (! process_section_headers (filedata))
|
||||
{
|
||||
|
|
@ -21490,6 +21475,7 @@ process_object (Filedata * filedata)
|
|||
if (! process_arch_specific (filedata))
|
||||
res = false;
|
||||
|
||||
out:
|
||||
free_filedata (filedata);
|
||||
|
||||
free_debug_memory ();
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue