asan: readelf: process_mips_specific buffer overflow

DT_MIPS_OPTIONS is not a regular array as assumed by readelf.  This
patch corrects that assumption, and to do so easily, makes various
internal (host byte order) structs the same size as external (target
byte order) structs.

include/
	* elf/mips.h (Elf32_RegInfo): Use fixed width integer types.
	(Elf64_Internal_RegInfo, Elf_Internal_Options): Likewise.
binutils/
	* readelf.c (process_mips_specific): Assert size of internal
	types match size of external types, and simplify allocation of
	internal buffer.  Catch possible integer overflow when sanity
	checking option size.  Don't assume options are a regular array.
	Sanity check reginfo option against option size.  Use PRI macros
	when printing.
This commit is contained in:
Alan Modra 2020-06-11 13:27:50 +09:30
parent ec16513e31
commit d0c4e7802d
4 changed files with 49 additions and 34 deletions

View File

@ -1,3 +1,12 @@
2020-06-11 Alan Modra <amodra@gmail.com>
* readelf.c (process_mips_specific): Assert size of internal
types match size of external types, and simplify allocation of
internal buffer. Catch possible integer overflow when sanity
checking option size. Don't assume options are a regular array.
Sanity check reginfo option against option size. Use PRI macros
when printing.
2020-06-10 Ralf Habacker <ralf.habacker@freenet.de>
PR 26082

View File

@ -16896,10 +16896,11 @@ process_mips_specific (Filedata * filedata)
{
Elf_Internal_Options * iopt;
Elf_Internal_Options * option;
Elf_Internal_Options * iopt_end;
iopt = (Elf_Internal_Options *)
cmalloc ((sect->sh_size / sizeof (eopt)), sizeof (* iopt));
assert (sizeof (Elf_Internal_Options) == sizeof (Elf_External_Options));
assert (sizeof (Elf32_RegInfo) == sizeof (Elf32_External_RegInfo));
assert (sizeof (Elf64_Internal_RegInfo) == sizeof (Elf64_External_RegInfo));
iopt = (Elf_Internal_Options *) cmalloc (sect->sh_size, 1);
if (iopt == NULL)
{
error (_("Out of memory allocating space for MIPS options\n"));
@ -16909,7 +16910,6 @@ process_mips_specific (Filedata * filedata)
offset = cnt = 0;
option = iopt;
iopt_end = iopt + (sect->sh_size / sizeof (eopt));
while (offset <= sect->sh_size - sizeof (* eopt))
{
@ -16924,7 +16924,7 @@ process_mips_specific (Filedata * filedata)
/* PR 17531: file: ffa0fa3b. */
if (option->size < sizeof (* eopt)
|| offset + option->size > sect->sh_size)
|| option->size > sect->sh_size - offset)
{
error (_("Invalid size (%u) for MIPS option\n"),
option->size);
@ -16943,18 +16943,18 @@ process_mips_specific (Filedata * filedata)
cnt),
printable_section_name (filedata, sect), cnt);
option = iopt;
offset = 0;
while (cnt-- > 0)
{
size_t len;
option = (Elf_Internal_Options *) ((char *) iopt + offset);
switch (option->kind)
{
case ODK_NULL:
/* This shouldn't happen. */
printf (" NULL %d %lx", option->section, option->info);
printf (" NULL %" PRId16 " %" PRIx32,
option->section, option->info);
break;
case ODK_REGINFO:
@ -16965,7 +16965,8 @@ process_mips_specific (Filedata * filedata)
Elf32_RegInfo reginfo;
/* 32bit form. */
if (option + 2 > iopt_end)
if (option->size < (sizeof (Elf_External_Options)
+ sizeof (Elf32_External_RegInfo)))
{
printf (_("<corrupt>\n"));
error (_("Truncated MIPS REGINFO option\n"));
@ -16982,10 +16983,11 @@ process_mips_specific (Filedata * filedata)
reginfo.ri_cprmask[3] = BYTE_GET (ereg->ri_cprmask[3]);
reginfo.ri_gp_value = BYTE_GET (ereg->ri_gp_value);
printf ("GPR %08lx GP 0x%lx\n",
reginfo.ri_gprmask,
(unsigned long) reginfo.ri_gp_value);
printf (" CPR0 %08lx CPR1 %08lx CPR2 %08lx CPR3 %08lx\n",
printf ("GPR %08" PRIx32 " GP 0x%" PRIx32 "\n",
reginfo.ri_gprmask, reginfo.ri_gp_value);
printf (" "
" CPR0 %08" PRIx32 " CPR1 %08" PRIx32
" CPR2 %08" PRIx32 " CPR3 %08" PRIx32 "\n",
reginfo.ri_cprmask[0], reginfo.ri_cprmask[1],
reginfo.ri_cprmask[2], reginfo.ri_cprmask[3]);
}
@ -16995,7 +16997,8 @@ process_mips_specific (Filedata * filedata)
Elf64_External_RegInfo * ereg;
Elf64_Internal_RegInfo reginfo;
if (option + 2 > iopt_end)
if (option->size < (sizeof (Elf_External_Options)
+ sizeof (Elf64_External_RegInfo)))
{
printf (_("<corrupt>\n"));
error (_("Truncated MIPS REGINFO option\n"));
@ -17011,16 +17014,15 @@ process_mips_specific (Filedata * filedata)
reginfo.ri_cprmask[3] = BYTE_GET (ereg->ri_cprmask[3]);
reginfo.ri_gp_value = BYTE_GET (ereg->ri_gp_value);
printf ("GPR %08lx GP 0x",
reginfo.ri_gprmask);
printf_vma (reginfo.ri_gp_value);
printf ("\n");
printf (" CPR0 %08lx CPR1 %08lx CPR2 %08lx CPR3 %08lx\n",
printf ("GPR %08" PRIx32 " GP 0x%" PRIx64 "\n",
reginfo.ri_gprmask, reginfo.ri_gp_value);
printf (" "
" CPR0 %08" PRIx32 " CPR1 %08" PRIx32
" CPR2 %08" PRIx32 " CPR3 %08" PRIx32 "\n",
reginfo.ri_cprmask[0], reginfo.ri_cprmask[1],
reginfo.ri_cprmask[2], reginfo.ri_cprmask[3]);
}
++option;
offset += option->size;
continue;
case ODK_EXCEPTIONS:
@ -17089,20 +17091,20 @@ process_mips_specific (Filedata * filedata)
break;
case ODK_GP_GROUP:
printf (" GP_GROUP %#06lx self-contained %#06lx",
printf (" GP_GROUP %#06x self-contained %#06x",
option->info & OGP_GROUP,
(option->info & OGP_SELF) >> 16);
break;
case ODK_IDENT:
printf (" IDENT %#06lx self-contained %#06lx",
printf (" IDENT %#06x self-contained %#06x",
option->info & OGP_GROUP,
(option->info & OGP_SELF) >> 16);
break;
default:
/* This shouldn't happen. */
printf (" %3d ??? %d %lx",
printf (" %3d ??? %" PRId16 " %" PRIx32,
option->kind, option->section, option->info);
break;
}
@ -17121,7 +17123,6 @@ process_mips_specific (Filedata * filedata)
fputs ("\n", stdout);
offset += option->size;
++option;
}
free (iopt);
free (eopt);

View File

@ -1,3 +1,8 @@
2020-06-11 Alan Modra <amodra@gmail.com>
* elf/mips.h (Elf32_RegInfo): Use fixed width integer types.
(Elf64_Internal_RegInfo, Elf_Internal_Options): Likewise.
2020-06-06 Alan Modra <amodra@gmail.com>
* elf/ppc64.h (elf_ppc64_reloc_type): Rename

View File

@ -560,11 +560,11 @@ typedef union
typedef struct
{
/* Mask of general purpose registers used. */
unsigned long ri_gprmask;
uint32_t ri_gprmask;
/* Mask of co-processor registers used. */
unsigned long ri_cprmask[4];
uint32_t ri_cprmask[4];
/* GP register value for this object file. */
long ri_gp_value;
uint32_t ri_gp_value;
} Elf32_RegInfo;
/* The external version of the Elf_RegInfo structure. */
@ -1008,9 +1008,9 @@ typedef struct
/* Size of option descriptor, including header. */
unsigned char size;
/* Section index of affected section, or 0 for global option. */
unsigned short section;
uint16_t section;
/* Information specific to this kind of option. */
unsigned long info;
uint32_t info;
} Elf_Internal_Options;
/* MIPS ELF option header swapping routines. */
@ -1074,13 +1074,13 @@ typedef struct
typedef struct
{
/* Mask of general purpose registers used. */
unsigned long ri_gprmask;
uint32_t ri_gprmask;
/* Padding. */
unsigned long ri_pad;
uint32_t ri_pad;
/* Mask of co-processor registers used. */
unsigned long ri_cprmask[4];
uint32_t ri_cprmask[4];
/* GP register value for this object file. */
bfd_vma ri_gp_value;
uint64_t ri_gp_value;
} Elf64_Internal_RegInfo;
/* ABI Flags structure version 0. */